StemCell Therapy

Onchocerciasis ( or ), also known as river blindness and Robles disease, is a disease caused by infection with the parasitic worm Onchocerca volvulus.[1] Symptoms include severe itching, bumps under the skin, and blindness.[1] It is the second most common cause of blindness due to infection, after trachoma.[2]

The parasite worm is spread by the bites of a black fly of the Simulium type.[1] Usually many bites are required before infection occurs.[3] These flies live near rivers therefore the name of the disease.[2] Once inside a person the worms create larvae that make their way out to the skin.[1] Here they can infect the next black fly that bites the person.[1] There are a number of ways to make the diagnosis including: placing a biopsy of the skin in normal saline and watching for the larva to come out, looking in the eye for larvae, and looking within the bumps under the skin for adult worms.[4]

A vaccine against the disease does not exist.[1] Prevention is by avoiding being bitten by flies.[5] This may include the use of insect repellent and proper clothing.[5] Other efforts include those to decrease the fly population by spraying insecticides.[1] Efforts to eradicate the disease by treating entire groups of people twice a year is ongoing in a number of areas of the world.[1] Treatment of those infected is with the medication ivermectin every six to twelve months.[1][6] This treatment kills the larva but not the adult worms.[7] The medication doxycycline, which kills an associated bacterium called Wolbachia, appears to weaken the worms and is recommended by some as well.[7] Removal of the lumps under the skin by surgery may also be done.[6]

About 17 to 25 million people are infected with river blindness, with approximately 0.8 million having some amount of loss of vision.[3][7] Most infections occur in sub-Saharan Africa, although cases have also been reported in Yemen and isolated areas of Central and South America.[1] In 1915, the physician Rodolfo Robles first linked the worm to eye disease.[8] It is listed by the World Health Organization as a neglected tropical disease.[9]

Adult worms remain in subcutaneous nodules, limiting access to the host's immune system.[citation needed] Microfilariae, in contrast, are able to induce intense inflammatory responses, especially upon their death. Wolbachia species have been found to be endosymbionts of O. volvulus adults and microfilariae, and are thought to be the driving force behind most of O. volvulus morbidity. Dying microfilariae have been recently discovered to release Wolbachia surface protein that activates TLR2 and TLR4, triggering innate immune responses and producing the inflammation and its associated morbidity.[10] The severity of illness is directly proportional to the number of infected microfilariae and the power of the resultant inflammatory response.[citation needed]

Skin involvement typically consists of intense itching, swelling, and inflammation.[11] A grading system has been developed to categorize the degree of skin involvement:[12][13][verification needed]

Ocular involvement provides the common name associated with onchocerciasis, river blindness, and may involve any part of the eye from conjunctiva and cornea to uvea and posterior segment, including the retina and optic nerve.[11] The microfilariae migrate to the surface of the cornea. Punctate keratitis occurs in the infected area. This clears up as the inflammation subsides. However, if the infection is chronic, sclerosing keratitis can occur, making the affected area become opaque. Over time, the entire cornea may become opaque, thus leading to blindness. Some evidence suggests the effect on the cornea is caused by an immune response to bacteria present in the worms.[citation needed] The skin is itchy, with severe rashes permanently damaging patches of skin.

The Mazzotti reaction, first described in 1948, is a symptom complex seen in patients after undergoing treatment of onchocerciasis with the medication diethylcarbamazine(DEC). Mazzotti reactions can be life-threatening, and are characterized by fever, urticaria, swollen and tender lymph nodes, tachycardia, hypotension, arthralgias, oedema, and abdominal pain that occur within seven days of treatment of microfilariasis.

The phenomenon is so common when DEC is used that this drug is the basis of a skin patch test used to confirm that diagnosis. The drug patch is placed on the skin, and if the patient is infected with O. volvulus microfilaria, localized pruritus and urticaria are seen at the application site.[14]

This is an unusual form of epidemic epilepsy associated with onchocerciasis.[15] This syndrome was first described in Tanzania by Louise Jilek-Aall, a Norwegian psychiatric doctor in Tanzanian practice, during the 1960s. It occurs most commonly in Uganda and South Sudan.

See the article here:
Onchocerciasis - Wikipedia, the free encyclopedia

Bonilla-Silva, E. (2006). Color-blind Racism and the Persistence of Racial Inequality in the United States (2nd Ed.). (Ch. 3: The style of color blindness: How to talk nasty about minorities without sounding racist, pp. 53-74)

Abstract Liberalism: involves using ideas associated with political liberalism and economic liberalism in an abstract manner to explain racial matters.

Naturalization: allows whites to explain away racial phenomena by suggesting they are natural occurrences.

Naturalization is a frame that allows whites to explain away racial phenomena by suggesting they are natural occurrences for example whites can claim segregation is natural because people from all backgrounds gravitate toward likeness. Although, the above statements can be interpreted as racist and as contradicting the colorblind logic they are used to reinforce the myth of nonracialism. How? by suggesting these preferences are almost biologically driven and typical of all groups in society, preferences for primary associations with members of ones race are rationalized as nonracial because they (racial minorities) do it too (p. 28).

Cultural Racism: relies on culturally based arguments to explain the standing of minorities in society.

Cultural racism is a frame that relies on culturally based arguments (p. 28)

Minimization of Racism: suggests discrimination is no longer a central factor affecting minorities life choices.

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The Four Frames of Color-Blindness Laura Bestler

"I can't believe he didn't suspect a trap. See what happens when you don't watch enough television?" A condition afflicting many fictional characters, seen when one demonstrates by their behavior that they have never in their life ever seen the kind of story they're in, and thus have none of the reactions a typical audience member would have in the same situation. Worse, they are unable to learn from any experiences related to their genre. Genre Blindness is what keeps the cast of Threes Company leaping to outrageous conclusions even after the hundredth stupid misunderstanding, instead of sitting down and talking things out. It makes young girls go for walks alone in the woods after midnight without a flashlight or a weapon when there's an axe murderer or a vampire around. It makes the supergenius supervillains in James Bond movies stuff the hero into an elaborate melodramatic Death Trap from which he inevitably escapes instead of just shooting him. Although genre blindness can be a legitimate flaw, it should be noted that it can be difficult for writers to create characters who are not genre blind without hanging a lampshade on it by saying something like "This is just like in the movies!", especially in genres which require suspense that can easily be undone by such comedic relief (such as horrors, thrillers, etc). Furthermore, some stories in some genres really couldn't function at all if the characters displayed an innate and complete understanding of what genre they were in and exactly how they should act at all times within a story in said genre if they want to avoid trouble. A certain amount of Genre Blindness can be required to provide the story with tension and drama, since if the character knows exactly what to do to avoid trouble and conflict in their particular story, they'll do it, and consequently have an easy, trouble-free life, and... why are we watching again? Finally, not all of a genre's classic tropes are in fact Truth in Television, but as far as the characters are concerned, This Is Reality, so their "blindness" may be the same as common sense. For example, in real life, a single cough usually does not herald a fatal disease, so It's Probably Nothing is probably rational despite being Genre Blind. Ultimately, while it can be a problem if used too egregiously, sometimes you just have to shrug your shoulders and chalk it up to Willing Suspension of Disbelief. Related:

open/close all folders

Anime and Manga

Comic Books

Fairy Tales

Fan Fiction

Film-Animated

Film-Live Action

"You best start believing in ghost stories, Miss Turner. You're in one!"

"First, your return to shore was not part of our negotiations nor our agreement so I "must" do nothing. And secondly, you must be a pirate for the pirate's code to apply and you're not. And thirdly, the code is more what you'd call 'guidelines' than actual rules. Welcome aboard the Black Pearl, Miss Turner."

See the rest here:
Genre Blindness - TV Tropes

Prosopagnosia (Greek: "prosopon" = "face", "agnosia" = "not knowing"), also called face blindness,[1] is a cognitive disorder of face perception where the ability to recognize faces is impaired, while other aspects of visual processing (e.g., object discrimination) and intellectual functioning (e.g., decision making) remain intact. The term originally referred to a condition following acute brain damage (acquired prosopagnosia), but a congenital or developmental form of the disorder also exists, which may affect up to 2.5% of the population.[2] The specific brain area usually associated with prosopagnosia is the fusiform gyrus,[3] which activates specifically in response to faces. The functionality of the fusiform gyrus allows most people to recognize faces in more detail than they do similarly complex inanimate objects. For those with prosopagnosia, the new method for recognizing faces depends on the less-sensitive object recognition system. The right hemisphere fusiform gyrus is more often involved in familiar face recognition than the left. It remains unclear whether the fusiform gyrus is only specific for the recognition of human faces or if it is also involved in highly trained visual stimuli.

There are two types of prosopagnosia: acquired and congenital (developmental). Acquired prosopagnosia results from occipito-temporal lobe damage and is most often found in adults. This is further subdivided into apperceptive and associative prosopagnosia. In congenital prosopagnosia, the individual never adequately develops the ability to recognize faces.[4]

Though there have been several attempts at remediation, no therapies have demonstrated lasting real-world improvements across a group of prosopagnosics. Prosopagnosics often learn to use "piecemeal" or "feature-by-feature" recognition strategies. This may involve secondary clues such as clothing, gait, hair color, body shape, and voice. Because the face seems to function as an important identifying feature in memory, it can also be difficult for people with this condition to keep track of information about people, and socialize normally with others. Prosopagnosia has also been associated with other disorders that are associated with nearby brain areas: left hemianopsia (loss of vision from left side of space, associated with damage to the right occipital lobe), achromatopsia (a deficit in color perception often associated with unilateral or bilateral lesions in the temporo-occipital junction) and topographical disorientation (a loss of environmental familiarity and difficulties in using landmarks, associated with lesions in the posterior part of the parahippocampal gyrus and anterior part of the lingual gyrus of the right hemisphere).[5]

Apperceptive prosopagnosia has typically been used to describe cases of acquired prosopagnosia with some of the earliest processes in the face perception system. The brain areas thought to play a critical role in apperceptive prosopagnosia are right occipital temporal regions.[6] People with this disorder cannot make any sense of faces and are unable to make same-different judgments when they are presented with pictures of different faces. They are unable to recognize both familiar and unfamiliar faces. However, they may be able to recognize people based on non-face clues such as their clothing, hairstyle or voice.[7]

Associative prosopagnosia has typically been used to describe cases of acquired prosopagnosia with spared perceptual processes but impaired links between early face perception processes and the semantic information we hold about people in our memories. Right anterior temporal regions may also play a critical role in associative prosopagnosia.[6] People with this form of the disorder may be able to say whether photos of people's faces are the same or different and derive the age and sex from a face (suggesting they can make sense of some face information) but may not be able to subsequently identify the person or provide any information about them such as their name, occupation, or when they were last encountered.[6]

Developmental prosopagnosia (DP), also called Congenital prosopagnosia (CP), is a face-recognition deficit that is lifelong, manifesting in early childhood, and that cannot be attributed to acquired brain damage. A number of studies have found functional deficits in DP both on the basis of EEG measures and fMRI. It has been suggested that a genetic factor is responsible for the condition. The term hereditary prosopagnosia was introduced if DP affected more than one family member, essentially accenting the possible genetic contribution of this condition. To examine this possible genetic factor, 689 randomly selected students were administered a survey in which seventeen developmental prosopagnosics were quantifiably identified. Family members of fourteen of the DP individuals were interviewed to determine prosopagnosia-like characteristics, and in all fourteen families, at least one other affected family member was found.[8]

In 2005, a study led by Ingo Kennerknecht showed support for the proposed congenital disorder form of prosopagnosia. This study provides epidemiological evidence that congenital prosopagnosia is a frequently occurring cognitive disorder that often runs in families. The analysis of pedigree trees formed within the study also indicates that the segregation pattern of hereditary prosopagnosia (HPA) is fully compatible with autosomal dominant inheritance. This mode of inheritance explains why HPA is so common among certain families (Kennerknecht et al. 2006).[9]

There are many developmental disorders associated with an increased likelihood that the person will have difficulties in face perception, of which the person may or may not be aware. The mechanism by which these perceptual deficits take place is largely unknown. A partial list of some disorders that often have prosopagnosiac components would include nonverbal learning disorder, Alzheimer's Disease, and autism spectrum disorders in general. However, these types of disorders are very complicated, so arbitrary assumptions should be avoided.[10]

Prosopagnosia can be caused by lesions in various parts of the inferior occipital areas (occipital face area), fusiform gyrus (fusiform face area), and the anterior temporal cortex.[6] Positron emission topography (PET) and fMRI scans have shown that, in individuals without prosopagnosia, these areas are activated specifically in response to face stimuli.[5] The inferior occipital areas are mainly involved in the early stages of face perception and the anterior temporal structures integrate specific information about the face, voice, and name of a familiar person.[6]

Acquired prosopagnosia can develop as the result of several neurologically damaging causes. Vascular causes of prosopagnosia include posterior cerebral artery infarcts (PCAIs) and hemorrhages in the infero-medial part of the temporo-occipital area. These can be either bilateral or unilateral, but if they are unilateral, they are almost always in the right hemisphere.[5] Recent studies have confirmed that right hemisphere damage to the specific temporo-occipital areas mentioned above is sufficient to induce prosopagnosia. MRI scans of patients with prosopagnosia showed lesions isolated to the right hemisphere, while fMRI scans showed that the left hemisphere was functioning normally.[5] Unilateral left temporo-occipital lesions result in object agnosia, but spare face recognition processes, although a few cases have been documented where left unilateral damage resulted in prosopagnosia. It has been suggested that these face recognition impairments caused by left hemisphere damage are due to a semantic defect blocking retrieval processes that are involved in obtaining person-specific semantic information from the visual modality.[6]

Continued here:
Prosopagnosia - Wikipedia, the free encyclopedia

Maybe you are thinking that all of color blind people see the world consisting of black and white only. But actually not, not all of the patients are suffered from total color blindness. In fact, the majority of them were suffer from partial color blindness. It means, they can still see colors, but not as complete as a normal person.

There are three types of partial color blindness: Deuteranopia, Protanopia and Tritanopia. Again, they, who are suffered from one of this type, could see colors too. However, for certain colors, they have difficulties in distinguishing them. For example, Protanopia and Deuteranopia have difficulties to distinguish green from red colors, thats why these types of color blindness are also called as red-green defficiency or red-green color blindness. Whereas, Tritanopia has difficulties to distinguish colors in bluish color spectrum.

All of them are caused by the lackness of one of three cone cells. Cone cells are responsible to absorb lights and activate color pigments. In normal conditions, eyes retina contains all of three cones. They are S-cones, M-cones and L-cones, they are also reffered to Blue- Cones, Green-Cones and Red-Cones respectively. To see colors completely, we need all of those cones presences to work together. They process color information captured by retina and then this information will be sent to brain to be perceived. The lackness of three types of cone cells, even only one cell, results incomplete color information for brain. This condition of lackness often called as color blindness.

This article will not reveal about how and the cause of color blindness in detail. Because it will need so many technically words and phrase. We are talking about how color blindness perceive colors. What is the difference between colorblind and normal color perception? Why are they cannot pass the Ishihara test, which is the common test for color blindness. We need a simulation to understand colorblindness color perception.

These are the simulation:

Simulation 1. Rainbow Colors

We can see that color blindness could see colors, couldnt they? But the simulation reveals that color blind perception of colorblindness are differ to that of normal color vision. We can see Deuteranop and Protanop color perceptions are almost similar to each other, their color spectrum is only consists of two colors: red and green. Deuteranop and Protanop will perceive Yellow, Green and Red color to yellowish color, which are differ only in brightness. Whereas, blue colors are not affected very much, they are still blue.

For Tritanop, who is lack of S-cone or Blue-Cones, confuse blue with green and yellow with violet.

Simulation 2, Color of Pencils

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How are color blindness see the rainbow? - For...

Blindness facts Blindness is strictly defined as the state of being totally sightless in both eyes. A completely blind individual is unable to see at all. The word blindness, however, is commonly used as a relative term to signify visual impairment, or low vision, meaning that even with eyeglasses, contact lenses, medicine or surgery, a person does not see well. Vision impairment can range from mild to severe. Worldwide, between 300 million and 400 million people are visually impaired due to various causes. Of this group, approximately 50 million people are totally blind, unable to see light in either eye. Eighty percent of blindness occurs in people over 50 years old. Common causes of blindness include diabetes, macular degeneration, traumatic injuries, infections, glaucoma, and inability to obtain any glasses. Less common causes of blindness include vitamin A deficiency, retinopathy of prematurity, vascular disease involving the retina or optic nerve including stroke, ocular inflammatory disease, retinitis pigmentosa, primary or secondary malignancies of the eye, congenital abnormalities, hereditary diseases of the eye, and chemical poisoning from toxic agents such as methanol. Temporary blindness differs in causes from permanent blindness. The diagnosis of blindness is made by examination of all parts of the eye by an ophthalmologist. The universal symptom of blindness or visual impairment is difficulty with seeing. People who lose their vision suddenly, rather than over a period of years, are more symptomatic regarding their visual loss. The treatment of blindness depends on the cause of blindness. The prognosis for blindness is dependent on its cause. Legal blindness is defined by lawmakers in nations or states in order to either limit allowable activities, such as driving, of individuals who are "legally blind" or to provide preferential governmental benefits to those people in the form of special educational services, assistance with daily functions or monetary assistance. It is estimated that approximately 700,000 people in the United States meet the legal definition of blindness. In most states in the United States, "legal blindness" is defined as the inability to see at least 20/200 in either eye with best optical correction. Between 80%-90% of the blindness in the world is preventable through a combination of education, access to good medical care, and provision of glasses. Patients who have untreatable blindness require reorganization of their habits and re-education to allow them to do everyday tasks in different ways. In the United States and most other developed nations, financial assistance through various agencies can pay for the training and support necessary to allow a blind person to function. There are countless individuals with blindness, who, despite significant visual handicaps, have had full lives and enriched the lives of those who have had contact with them. What is blindness?

Blindness is defined as the state of being sightless. A blind individual is unable to see. In a strict sense the word "blindness" denotes the inability of a person to distinguish darkness from bright light in either eye. The terms blind and blindness have been modified in our society to include a wide range of visual impairment. Blindness is frequently used today to describe severe visual decline in one or both eyes with maintenance of some residual vision.

Vision impairment, or low vision, means that even with eyeglasses, contact lenses, medicine, or surgery, someone doesn't see well. Vision impairment can range from mild to severe. Worldwide, between 300 million-400 million people are visually impaired due to various causes. Of this group, approximately 50 million people are totally blind. Approximately 80% of blindness occurs in people over 50 years of age.

Medically Reviewed by a Doctor on 2/25/2015

Blindness - Causes Question: Please discuss the cause of blindness in a relative or friend?

Blindness - Diagnosis Question: Discuss the events that led to a diagnosis of blindness.

Blindness - Treatment Question: Please discuss treatments for blindness received by you or someone you know.

Blindness - Legally Blind Question: Please discuss in what ways being "legally blind" has affected your lifestyle.

Medical Author:

Andrew A. Dahl, MD, is a board-certified ophthalmologist. Dr. Dahl's educational background includes a BA with Honors and Distinction from Wesleyan University, Middletown, CT, and an MD from Cornell University, where he was selected for Alpha Omega Alpha, the national medical honor society. He had an internal medical internship at the New York Hospital/Cornell Medical Center.

The rest is here:
Blindness: Get Facts About Causes of Vision Loss

Blindness is a 2008 Canadian film in English. It is an adaptation of the 1995 novel of the same name by Portuguese author Jos Saramago about a society suffering an epidemic of blindness. The film was written by Don McKellar and directed by Fernando Meirelles with Julianne Moore and Mark Ruffalo as the main characters. Saramago originally refused to sell the rights for a film adaptation, but the producers were able to acquire it with the condition that the film would be set in an unnamed and unrecognizable city. Blindness premiered as the opening film at the Cannes Film Festival on May 14, 2008, and the film was released in the United States on October 3, 2008.

In an unnamed city, a young Japanese professional (Yusuke Iseya) is suddenly struck blind for no apparent reason. The Japanese man is approached by a few concerned people, one of whom (Don McKellar) offers to drive him home, and later steals his car. The blinded man describes his sudden affliction: an expanse of dazzling white, as though he is "swimming in milk".

Upon arriving home later that evening and noticing her husband's blindness, the Japanese man's wife (Yoshino Kimura) takes him to a local ophthalmologist (Mark Ruffalo) who, after testing the man's eyes, can identify nothing wrong with his sight and recommends further evaluation at a hospital. Among the doctor's patients are an old man with a black eye-patch (Danny Glover), a woman with dark glasses (Alice Braga), and a young boy (Mitchell Nye).

During a dinner with his wife (Julianne Moore), the doctor discusses the strange case of sudden blindness that hit the Japanese man. Elsewhere in the city, the woman with dark glassesrevealed to be a call-girlbecomes the third victim of the strange blindness after an appointment with a john in a luxury hotel.

The next day, the doctor wakes up to realize that he too has gone blind. In various locations around the city, more citizens are struck blind, causing widespread panic, and the government organizes a quarantine for the blind in a local derelict asylum. When a hazmat crew arrives to pick up the doctor, his wife climbs into the van with him, lying that she has also gone blind in order to accompany him into isolation.

In the asylum, the doctor and his wife are first to arrive and both agree they will keep her sight a secret. Several others arrive: the woman with dark glasses, the Japanese man, the car thief, and the young boy. The doctor's wifewho continues to remain sightedcomes across the old man with the eye-patch, who describes the condition of the world outside. The sudden blindness, known only as the "white sickness", is now international, with hundreds of cases being reported every day. Desperate by this point, the increasingly totalitarian government resorts to increasingly ruthless measures to try to staunch the epidemic, refusing the sick any aid or medicines.

In due course, as more and more blind people are crammed into the fetid prison, overcrowding and total lack of any outside support cause the hygiene and living conditions to degrade horrifically in a short time. Soon, the walls and floors are caked in filth and human feces. Anxiety over the availability of food, caused by irregular deliveries, undermines the morale inside. The lack of organization prevents the blind internees from fairly distributing food among each other. The soldiers who guard the asylum become increasingly hostile.

Living conditions degenerate even further when an armed clique of men, led by an ex-barman who declares himself the king of ward 3 (Gael Garca Bernal), gains control over the sparse deliveries of food. The MRE rations are distributed only in exchange for valuables, and then for the women of the other wards. Faced with starvation, the doctor's wife snaps and murders the king of ward 3. His death initiates a chaotic war between the wards, which culminates with the asylum being burned down and most of the inmates die in the fire. Only then do the few survivors discover that the military have abandoned their posts and they are free to venture into the city.

Society has fallen as the entire population is blind amid a city devastated and overrun with filth and dead bodies. The doctor's wife leads her husband and several others in search of food and shelter. The doctor and his wife arrive in a supermarket filled with stumbling blind people, and they find food in a basement storeroom. As she prepares to leave and meet her husband outside, she is attacked by the starving people who smell the food she is carrying. Her husband, now used to his blindness, saves her and they manage to return to their friends.

The doctor and his wife with their new "family" eventually make their way back to the house of the doctor, where they establish a permanent home. Just as suddenly as his sight had been lost, the Japanese man recovers his sight one morning. As the friends all celebrate, the doctor's wife stands out on the porch, staring up into a white overcast sky and for a moment appears to be going blind herself until the video camera shifts downwards, revealing that she sees the cityscape before her.

Read this article:
Blindness (film) - Wikipedia, the free encyclopedia

Have you ever put on a blindfold and pretended that you couldn't see? You probably bumped into things and got confused about which way you were going. But if you had to, you could get adjusted and learn to live without your sight.

Lots of people have done just that. They have found ways to learn, play, and work, even though they have trouble seeing or can't see at all.

Your eyes and your brain work together to see. The eye is made up of many different parts, including the cornea, iris, lens, and retina. These parts all work together to focus on light and images. Your eyes then use special nerves to send what you see to your brain, so your brain can process and recognize what you're seeing. In eyes that work correctly, this process happens almost instantly.

When this doesn't work the way it should, a person may be visually impaired, or blind. The problem may affect one eye or both eyes.

When you think of being blind, you might imagine total darkness. But most people who are blind can still see a little light or shadows. They just can't see things clearly. People who have some sight, but still need a lot of help, are sometimes called "legally blind."

Vision problems can develop before a baby is born. Sometimes, parts of the eyes don't form the way they should. A kid's eyes might look fine, but the brain has trouble processing the information they send. The optic nerve sends pictures to the brain, so if the nerve doesn't form correctly, the baby's brain won't receive the messages needed for sight.

Blindness can be genetic (or inherited), which means that this problem gets passed down to a kid from parents through genes.

Blindness also can be caused by an accident, if something hurts the eye. That's why it's so important to protect your eyes when you play certain sports, such as hockey.

Some illnesses, such as diabetes, can damage a person's vision over time. Other eye diseases, such as cataracts (say: KAH-tuh-rakts), can cause vision problems or blindness, but they usually affect older people.

Continued here:
Blindness - KidsHealth

Summary: Users rarely look at display advertisements on websites. Of the 4 design elements that do attract a few ad fixations, one is unethical and reduces the value of advertising networks.

I've been reluctant to discuss one of the findings from our eyetracking research because the conclusion is that unethical design pays off.

In 1997, I chose to suppress a similar finding: users tend to click on banner ads that look like dialog boxes, complete with fake OK and Cancel buttons. Of course, instead of being an actual system message such as "Your Internet Connection Is Not Optimized" the banner is just a picture of a dialog box, and clicking its close box doesn't dismiss it, but rather takes users to the advertiser's site. Deceptive, unethical, and #3 among the most-hated advertising techniques. Still, fake dialog boxes got many more clicks than regular banners, which users had already started to ignore in 1997.

After much soul-searching, I've now decided to take a different approach and publish our new findings, despite their ethical implications. In reality, it's not possible to suppress research results because anybody who bothers to run the study will get the same findings. There are no secrets of usability any more than there are secrets of astronomy. If you point your telescope at Saturn, you will see that it has rings. And, if you conduct a series of usability studies, you will discover the same insights as we do assuming you employ the correct methodology.

Many people without a grounding in behavioral user-research principles use bogus methodology and thus get misleading findings. Poor methodology is especially common for eyetracking studies, and thus most published studies in this area are wrong.

For example, unskilled researchers often ask users to simply look at a page, rather than have them encounter it as part of a task flow. Users naturally look at things differently depending on the context. For example, if you want to know how users look at the elements of a form, you can't just present the form on a stand-alone page and ask them to fill it out. Instead, you have to present the form in the context of a meaningful task that they might attempt in the real world. That is, users should encounter the form in response to particular actions, such as deciding to check out from an e-commerce site.

Still, even though most eyetracking studies are misleading, some studies do produce valid results. Trying to keep any results a secret is thus a lost cause.

Most of our eyetracking findings on Web advertising present no ethical dilemmas. For example, we know that there are 3 design elements that are most effective at attracting eyeballs:

I don't have a problem presenting details of these findings in the seminar on Top Web UX Design Guidelines; it's important that all Web designers know where users look on pages.

The most prominent result from the new eyetracking studies is not actually new. We simply confirmed for the umpteenth time that banner blindness is real. Users almost never look at anything that looks like an advertisement, whether or not it's actually an ad. (Indeed, banner blindness is moving beyond the online realm, for example into ballot design.)

Read this article:
Banner Blindness: Old and New Findings, 10-year research ...

Format: Paperback

This novel is one of the best books that I have read all year. Saramago's concept of a world caught up in a disease of blindness was a brilliant one, but his accomplishments in making this event seem plausible are superior. The book's entire structure adds to the blind quality of the novel: The characters are unnamed, save for a vague moniker that breifly describes them (example: the girl with dark glasses, the old man with the black eye patch). The dialogue is unquoted and placed within the text, virtually unmarked. Chapters are unnamed, and the text is written in large, lengthy paragraphs, mimicking the fact that sensations would come with no breaks, that all would seem as one. The book's only downfall is its occasional difficulty. Though the prose is simply, elegantly written in a somewhat sparse style, its blocky format can be too much for some readers to handle at a time. As well, the unquoted, often unattributed dialogue can become confusing after a lengthy passage of conversation, as the reader is unable to tell who is speaking. Besides these minor pitfalls, this book truly resembles a modern retelling of many mythological stories, but with a tragically human bent that draws the readers in and makes them feel a part of the action. An excellent, thought-provoking read, worthy of any bibliophile's library. Enjoy.

Original post:
Blindness (Harvest Book): Jose Saramago: Amazon.com: Books

Blindness is the condition of poor visual perception.

Various scales have been developed to describe the extent of vision loss and define blindness.[1] Total blindness is the complete lack of form and visual light perception and is clinically recorded as NLP, an abbreviation for "no light perception."[1] Blindness is frequently used to describe severe visual impairment with some remaining vision. Those described as having only light perception have no more sight than the ability to tell light from dark and the general direction of a light source. The World Health Organization defines low vision as visual acuity of less than 20/60 (6/18), but equal to or better than 20/200 (6/60), or visual field loss to less than 20 degrees, in the better eye with best possible correction. Blindness is defined as visual acuity of less than 20/400 (6/120), or a visual field loss to less than 10 degrees, in the better eye with best possible correction.[2][3]

As of 2012 there were 285 million visually impaired people in the world, of which 246 million had low vision and 39 million were blind.[3] The majority of people with poor vision are in the developing world and are over the age of 50 years.[3]

Blindness is defined by the World Health Organization as vision in a person's best eye of less than 20/500 or a visual field of less than 10 degrees.[4] This definition was set in 1972, and there is ongoing discussion as to whether it should be altered somewhat.[5]

Blind people with undamaged eyes may still register light non-visually for the purpose of circadian entrainment to the 24-hour light/dark cycle. Light signals for this purpose travel through the retinohypothalamic tract and are not affected by optic nerve damage beyond where the retinohypothalamic tract exits.

In 1934, the American Medical Association adopted the following definition of blindness:

"Central visual acuity of 20/200 or less in the better eye with corrective glasses or central visual acuity of more than 20/200 if there is a visual field defect in which the peripheral field is contracted to such an extent that the widest diameter of the visual field subtends an angular distance no greater than 20 degrees in the better eye."[6]

The United States Congress included this definition as part of the Aid to the Blind program in the Social Security Act passed in 1935.[6][7] In 1972, the Aid to the Blind program and two others combined under Title XVI of the Social Security Act to form the Supplemental Security Income program[8] which currently states:

"An individual shall be considered to be blind for purposes of this title if he has central visual acuity of 20/200 or less in the better eye with the use of a correcting lens. An eye which is accompanied by a limitation in the fields of vision such that the widest diameter of the visual field subtends an angle no greater than 20 degrees shall be considered for purposes of the first sentence of this subsection as having a central visual acuity of 20/200 or less. An individual shall also be considered to be blind for purposes of this title if he is blind as defined under a State plan approved under title X or XVI as in effect for October 1972 and received aid under such plan (on the basis of blindness) for December 1973, so long as he is continuously blind as so defined."[9]

In the UK, the Certificate of Vision Impairment (CVI) is used to certify patients as severely sight impaired or sight impaired.[10] The accompanying guidance for clinical staff states: "The National Assistance Act 1948 states that a person can be certified as severely sight impaired if they are so blind as to be unable to perform any work for which eye sight is essential (National Assistance Act Section 64(1)). The test is whether a person cannot do any work for which eyesight is essential, not just his or her normal job or one particular job."[11]

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Blindness - Wikipedia, the free encyclopedia

If you have low vision, eyeglasses, contact lenses, medicine, or surgery may not help. Activities like reading, shopping, cooking, writing, and watching TV may be hard to do. The leading causes of low vision and blindness in the United States are age-related eye diseases: macular degeneration, cataract and glaucoma. Other eye disorders, eye injuries and birth defects can also cause vision loss.

Whatever the cause, lost vision cannot be restored. It can, however, be managed. A loss of vision means that you may have to reorganize your life and learn new ways of doing things. If you have some vision, visual aids such as special glasses and large print books can make life easier. There are also devices to help those with no vision, like text-reading software and braille books.

The sooner vision loss or eye disease is found and treated, the greater your chances of keeping your remaining vision. You should have regular comprehensive eye exams by an eye care professional.

NIH: National Eye Institute

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Vision Impairment and Blindness: MedlinePlus

From Nobel Prizewinning author Jos Saramago, a magnificent, mesmerizing parable of loss

A city is hit by an epidemic of "white blindness" that spares no one. Authorities confine the blind to an empty mental hospital, but there the criminal element holds everyone captive, stealing food rations and assaulting women. There is one eyewitness to this nightmare who guides her c

A city is hit by an epidemic of "white blindness" that spares no one. Authorities confine the blind to an empty mental hospital, but there the criminal element holds everyone captive, stealing food rations and assaulting women. There is one eyewitness to this nightmare who guides her chargesamong them a boy with no mother, a girl with dark glasses, a dog of tearsthrough the barren streets, and their procession becomes as uncanny as the surroundings are harrowing. As Blindness reclaims the age-old story of a plague, it evokes the vivid and trembling horrors of the twentieth century, leaving readers with a powerful vision of the human spirit that's bound both by weakness and exhilarating strength.

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Blindness (Blindness, #1) by Jos Saramago Reviews ...

Color blindness, or color vision deficiency, is the inability or decreased ability to see color, or perceive color differences, under normal lighting conditions. Color blindness affects a significant percentage of the population.[1] There is no actual blindness but there is a deficiency of color vision. The most usual cause is a fault in the development of one or more sets of retinal cones that perceive color in light and transmit that information to the optic nerve. This type of color blindness is usually a sex-linked condition. The genes that produce photopigments are carried on the X chromosome; if some of these genes are missing or damaged, color blindness will be expressed in males with a higher probability than in females because males only have one X chromosome (in females, a functional gene on only one of the two X chromosomes is sufficient to yield the needed photopigments).[2]

Color blindness can also be produced by physical or chemical damage to the eye, the optic nerve, or parts of the brain. For example, people with achromatopsia suffer from a completely different disorder, but are nevertheless unable to see colors.

The first scientific paper on this subject, Extraordinary facts relating to the vision of colours, was published by the English chemist John Dalton in 1798[3] after the realization of his own color blindness. Because of Dalton's work, the general condition has been called daltonism, although in English this term is now used only for deuteranopia.

Color blindness is usually classified as a mild disability, however there are occasional circumstances where it can give an advantage. Some studies conclude that color blind people are better at penetrating certain color camouflages. Such findings may give an evolutionary reason for the high prevalence of redgreen color blindness.[4] There is also a study suggesting that people with some types of color blindness can distinguish colors that people with normal color vision are not able to distinguish.[5]

Color blindness affects a large number of individuals, with protanopia and deuteranopia being the most common types.[6] In individuals with Northern European ancestry, as many as 8 percent of men and 0.4 percent of women experience congenital colour deficiency.[7] The typical human retina contains two kinds of light cells: the rod cells (active in low light) and the cone cells (active in normal daylight). Normally, there are three kinds of cone cells, each containing a different pigment, which are activated when the pigments absorb light. The spectral sensitivities of the cones differ; one is most sensitive to short wavelengths, one to medium wavelengths, and the third to medium-to-long wavelengths within the visible spectrum, with their peak sensitivities in the blue, green, and yellow-green regions of the spectrum, respectively. The absorption spectra of the three systems overlap, and combine to cover the visible spectrum. These receptors are often called S cones, M cones, and L cones, for short, medium, and long wavelength; but they are also often referred to as blue cones, green cones, and red cones, respectively.[8]

Although these receptors are often referred to as "blue, green, and red" receptors, this terminology is inaccurate. The receptors are each responsive to a wide range of wavelengths. For example, the long wavelength, "red", receptor has its peak sensitivity in the yellow-green, some way from the red end (longest wavelength) of the visible spectrum. The sensitivity of normal color vision actually depends on the overlap between the absorption ranges of the three systems: different colors are recognized when the different types of cone are stimulated to different degrees. Red light, for example, stimulates the long wavelength cones much more than either of the others, and reducing the wavelength causes the other two cone systems to be increasingly stimulated, causing a gradual change in hue.

Many of the genes involved in color vision are on the X chromosome, making color blindness much more common in males than in females because males only have one X chromosome, while females have two. Because this is an X-linked trait, an estimated 23% of women have a 4th color cone[9] and can be considered tetrachromats, although it is not clear that this provides an advantage in color discrimination.

Color vision deficiencies can be classified as acquired or inherited.

Based on clinical appearance, color blindness may be described as total or partial. Total color blindness is much less common than partial color blindness.[17] There are two major types of color blindness: those who have difficulty distinguishing between red and green, and who have difficulty distinguishing between blue and yellow.[18][19]

Immunofluorescent imaging is a way to determine red-green color coding. Conventional color coding is difficult for individuals with red-green color blindness (protanopia or deuteranopia) to discriminate. Replacing red with magenta (top[where?]) or green with turquoise (bottom[where?]) improves visibility for such individuals.[20][not in citation given]

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Color blindness - Wikipedia, the free encyclopedia

P-SPAN #411: "Treating Blindness with Stem Cells"
On February 5, 2015, the Science/Biotechnology Department at Berkeley City College kicked off their Spring 2015 Seminar Series, sponsored by the California Institute for Regenerative Medicine....

By: Peralta Colleges

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P-SPAN #411: "Treating Blindness with Stem Cells" - Video

Can Stem Cell Injections Cure Blindness?
Stem cells may be able to cure blindness through injecting them into the eyes of people who are blind. The procedure worked over a three year period in restoring the vision of eighteen patients...

By: TheLipTV

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Can Stem Cell Injections Cure Blindness? - Video

Stem Cells, Blindness And Why The Media Loves Miracle Cures
Scientists researching the safety of stem cells have found the cells can help improve sight in patients with vision impairments. Follow Sebastian Martinez: http://www.twitter.com/sebastiansings...

By: Newsy Science

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Stem Cells, Blindness And Why The Media Loves Miracle Cures - Video

Stem-cell treatment for blindness
A legally blind Bexley man will undergo an experimental eye procedure that offers the promise of better vision.

By: TheColumbusDispatch

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Stem-cell treatment for blindness - Video

Stem-cell help for blindness
A legally blind Bexley man will undergo an experimental eye procedure that offers the promise of better vision.

By: TheColumbusDispatch

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Stem-cell help for blindness - Video

Can Stem Cells Cure Blindness?
Scientists have collected stem cells that were primed to transform into photoreceptors then injected them into the eyes of blind mice.

By: NewsyScience

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Can Stem Cells Cure Blindness? - Video