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Genevieve Fox Paola Peretti is losing her eyesight and she wouldn’t have it any other way. When she was 14, she became very short-sighted, virtually overnight. Three years later came the diagnosis of Stargardt macular dystrophy, a degenerative disease that destroys central vision, damages colour perception and results in blindness. Two years ago, finding herself in a place of both “desperation and hope,” the 32-year-old Italian language teacher and debut novelist decided to step out from the shadow of her hereditary condition, which she only ever aired with her family, and confront her fear of the dark. The Distance Between Me and the Cherry Tree is the result: a captivating, wise and highly visual children’s novel about living in the face of fear. Its heroine, nine-year-old Mafalda, also has Stargardt disease. A bewitching, brave little girl, she will lose her sight completely within six months, as Peretti was expecting to do at some unspecified point in her own life when she began the novel. The eponymous cherry tree is next to Mafalda’s school. Each day, she has to get closer to it before it comes into focus. As her short-sightedness increases, so does her fear of the future. “She is losing her life as she knows it,” says Peretti, who explains that she herself can see “half of what other people see”. Mafalda has blank patches in both eyes, and they get bigger. Peretti has a blank patch in her right eye. I am seated a couple of feet from her as we talk in her publisher’s office. She says I am partially blurred. © 2018 Guardian News and Media Limited

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 11: Emotions, Aggression, and Stress
Link ID: 25352 - Posted: 08.20.2018

By Kelly Servick Nestled in the backs of our eyes, there are cells that might be able to repair damage from some vision-impairing diseases. But so far, scientists haven’t managed to kick them into gear. Now, a team of researchers claims to have prompted these cells, called Müller glia, to regenerate one type of light receptor cell in the eyes of mice. According to their study, published today in Nature, these new cells could detect incoming light and network with other cells in the eye to relay signals to the brain, a potential step toward reversing certain genetic eye conditions and injuries. But others are skeptical of that claim and argue the signals could have come from existing light-sensing cells in the eye—not new ones. “Nobody more than me wants this to be true,” says Seth Blackshaw, a neuroscientist at Johns Hopkins University’s School of Medicine in Baltimore, Maryland, “but I have serious concerns about this study.” The new work is part of a long effort to regenerate photoreceptors, neurons in the retina that transform incoming light into electrical signals. Cone receptors are responsible for our daytime vision and perception of colors, and the more sensitive rod receptors enable vision in low light. The destruction of these cells—or of the retinal ganglion cells that transmit their signals to the brain—can diminish vision and even cause blindness. © 2018 American Association for the Advancement of Science

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25340 - Posted: 08.16.2018

Scientists say they have found how blue light from smartphones, laptops and other digital devices damages vision and can speed up blindness. Research by the University of Toledo in the US has revealed that prolonged exposure to blue light triggers poisonous molecules to be generated in the eye’s light-sensitive cells that can cause macular degeneration – an incurable condition that affects the middle part of vision. Blue light, which has a shorter wavelength and more energy compared with other colours, can gradually cause damage to the eyes. Dr Ajith Karunarathne, an assistant professor in the university’s department of chemistry and biochemistry, said: “We are being exposed to blue light continuously and the eye’s cornea and lens cannot block or reflect it. “It’s no secret that blue light harms our vision by damaging the eye’s retina. Our experiments explain how this happens, and we hope this leads to therapies that slow macular degeneration, such as a new kind of eye drop.” Macular degeneration, which affects around 2.4% of the adult population in the UK, is a common condition among those in their 50s and 60s that results in significant vision loss. It is caused by the death of photoreceptor, ie light-sensitive cells, in the retina. Age-related macular degeneration is the leading cause of blindness in the US and while it does not cause total blindness, it can make everyday activities such as reading and recognising faces difficult. © 2018 Guardian News and Media Limite

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25315 - Posted: 08.10.2018

By Susana Martinez-Conde The house cricket (Acheta domesticus) walked around the arena comfortably, certain of its surroundings. It looked about, perhaps hoping for food or mates, ignoring the scattered, browning, dead leaves. On previous visits to the arena, the cricket had been wary of the dead leaves, not knowing what to make of them. Then, after a prudent interval, it had ventured to feel them with its segmented antennae—tentatively at first, and later with growing confidence. Once the cricket determined the leaves were neither edible nor harmful, it quickly lost interest in them. Now it rarely bothered to explore the leaves, but took no great pains to avoid them either. The cricket’s conviction about the safety of the leaves was its fatal mistake: on this visit, one seemingly dead leaf lying on the arena was no such, but a masquerading ghost mantis (Phyllocrania paradoxa) waiting in ambush. Unaware of the concealed peril, the cricket drew ever closer to the predator. That’s when the mantis struck forth, grasping the cricket by one of its long jumping legs. As the cricket struggled against the mantis’ clutch, the predator started to feed. Dr John Skelhorn, Lecturer in Animal Cognition, has witnessed dozens of similar life-and-death encounters in his lab at Newcastle University’s Institute of Neuroscience. Skelhorn and his colleagues previously found that some animals masquerade as inanimate, inedible objects, to look less appealing to potential predators. Some examples include the orb web spider (Cyclosa ginnaga) and the larva of the giant swallowtail butterfly (Papilio cresphontes), both of which masquerade as bird droppings, and the larva of the feathered thorn moth (Selenia dentaria), which masquerades as a twig. © 2018 Scientific American

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25299 - Posted: 08.06.2018

By Donald G. McNeil Jr. GETA, Nepal — Fifteen years ago, Shiva Lal Rana walked 20 miles to Geta Eye Hospital to ask doctors to pluck out all his eyelashes. Trachoma, a bacterial infection, had swollen and inverted his eyelids. With every blink, his lashes raked his corneas. “The scratching hurt my eyes so much I could barely go out in the sun to plow,” he said. “I was always rubbing them.” Worse, he feared the fate that others with the infection had suffered. The tiny scratches could accumulate and ultimately blind him. Instead, doctors performed what was then a new operation: They sliced open his eyelids, rolled them back and sutured them with the lashes facing outward again. And they gave him antibiotics to clear up the infection. “My vision is much better now,” said Mr. Rana, a tiny, lively man who guessed he was about 65. “I can recognize people. I can work.” His personal triumph parallels his nation’s. In May, the World Health Organization declared that Nepal had eliminated trachoma as a public health problem, making it the sixth country to do so. In June, Ghana became the seventh. Quietly, in the shadow of fights against better-known diseases like Ebola, AIDS and malaria, the 20-year battle against trachoma is chalking up impressive victories. Those successes, experts say, show the wisdom of advocating and enforcing basic public health practices, rather than waiting for a miracle cure or a new vaccine. © 2018 The New York Times Company

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25222 - Posted: 07.18.2018

By Smitha Mundasad Global Health Correspondent, BBC News For many years, Dr Andrew Bastawrous could not see clearly enough to spot the leaves on trees or the stars in the sky. Teachers kept telling him he was lazy and he kept missing the football during games. Then, aged 12, his mother took him to have his eyes tested and that changed everything. Now he is a prize-winning eye doctor with a plan to use a smartphone app to bring better vision to millions of children around the world. Dr Bastawrous told the BBC: "I'll never forget that moment at the optometrist. I had trial lenses on and looked across the car park and saw the gravel on the road had so much detail I had had no idea about. "A couple of weeks later I got my first pair of glasses and that's when I saw stars for first time, started doing well at school and it completely transformed my life." Around the world 12 million children, like Dr Bastawrous, have sight problems that could be corrected by a pair of glasses. But in many areas, access to eye specialists is difficult - leaving children with visual impairments that can harm school work and, ultimately, their opportunities in later life. In rural Kenya, for example, there is one eye doctor for one million people. Meanwhile in the US, there is on average one ophthalmologist for every 15,800 people. In 2011 Dr Bastawrous - by now an eye doctor in England - decided to study the eye health of the population of Kitale, Kenya, as part of his PhD. He took about £100,000 of eye equipment in an attempt to set up 100 temporary eye clinics but found this didn't work, as reliable roads and electricity were scarce. It was realising that these same areas had great mobile phone coverage - with about 80% of the population owning a cell phone - that sparked the idea for Peek. © 2018 BBC.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25204 - Posted: 07.14.2018

By JoAnna Klein Owl eyes are round, but not spherical. These immobile, tubular structures sit on the front of an owl’s face like a pair of built-in binoculars. They allow the birds to focus in on prey and see in three dimensions, kind of like humans — except we don’t have to turn our whole heads to spot a slice of pizza beside us. Although owls and humans both have binocular vision, it has been unclear whether these birds of prey process information they collect from their environments like humans, because their brains aren’t as complex. But in a study published in the Journal of Neuroscience on Monday, scientists tested the ability of barn owls to find a moving target among various shifting backgrounds, a visual processing task earlier tested only in primates. The research suggests that barn owls, with far simpler brains than humans and other primates, also group together different elements as they move in the same direction, to make sense of the world around them. “Humans are not so different from birds as you may think,” said Yoram Gutfreund, a neuroscientist at Technion Israel Institute of Technology who led the study with colleagues from his university and RWTH Aachen University in Germany. A critical part of perception is being able to distinguish an object from its background. One way humans do this is by grouping elements of a scene together to perceive each part as a whole. In some cases, that means combining objects that move similarly, like birds flying in a flock, or the single bird that breaks away from it. Scientists have generally considered this type of visual processing as a higher level task that requires complex brain structures. As such, they’ve only studied it in humans and primates. But Dr. Gutfreund and his team believed this ability was more basic — like seeing past camouflage. A barn owl, for example, might have evolved a similar mechanism to detect a mouse moving in a meadow as wind blows the grass in the same direction. © 2018 The New York Times Company

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 6: Evolution of the Brain and Behavior
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25174 - Posted: 07.05.2018

By Matt Warren Every day, humans make dozens of judgements, from deciding whether our clothes match to determining whether a shady character in the street is a threat. Such decisions aren’t based on hard-and-fast rules, a new study reveals. Instead, our concept of “threat”—and even of the color “blue”—is all relative. To make the find, researchers showed non–color-blind participants a series of 1000 dots ranging from very blue to very purple, and asked them to judge whether each dot was blue. For the first 200 trials, participants saw an equal number of dots from the blue and purple parts of the spectrum, but then the prevalence of blue dots gradually decreased to just a fraction of what it was before. By the end of the study, participants’ interpretation of the colors had changed: Dots that they had thought were purple in the first set of trials they now classified as blue, the authors report today in Science. That is, their concept of the color blue had expanded to also include shades of purple. Even when the researchers forewarned participants that blue dots would become rarer and promised them money if they kept their judgments consistent, the same shift occurred. And the team found similar results in more complex versions of the task, where participants had to judge whether a face was threatening or whether a research proposal was ethical. When threatening faces or unethical research proposals became less common, people started to consider previously benign examples as posing a threat or being unethical. © 2018 American Association for the Advancement of Science.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 14: Attention and Consciousness
Link ID: 25154 - Posted: 06.29.2018

By Roni Caryn Rabin Ever since he had Lasik surgery two years ago, Geobanni Ramirez sees everything in triplicate. The surgery he hoped would improve his vision left the 33-year-old graphic artist struggling with extreme light sensitivity, double vision and visual distortions that create halos around bright objects and turn headlights into blinding starbursts. His eyes are so dry and sore that he puts drops in every half-hour; sometimes they burn “like when you’re chopping onions.” His night vision is so poor that going out after dark is treacherous. But Mr. Ramirez says that as far as his surgeon is concerned, he is a success story. “My vision is considered 20/20, because I see the A’s, B’s and C’s all the way down the chart,” said Mr. Ramirez. “But I see three A’s, three B’s, three C’s.” None of the surgeons he consulted ever warned him he could sustain permanent damage following Lasik, he added. The Food and Drug Administration approved the first lasers to correct vision in the 1990s. Roughly 9.5 million Americans have had laser eye surgery, lured by the promise of a quick fix ridding them of nettlesome glasses and contact lenses. There is also a wide perception among patients, fostered by many eye doctors who do the surgery, that the procedure is virtually foolproof. As far back as 2008, however, patients who had received Lasik and their families testified at an F.D.A. meeting about impaired vision and chronic pain that led to job loss and disability, social isolation, depression — and even suicides. Even now, serious questions remain about both the short- and long-term risks and the complications of this increasingly common procedure. © 2018 The New York Times Company

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 25080 - Posted: 06.12.2018

By LISA SANDERS, M.D. The young woman rubbed her eyes. The numbers and letters on her computer screen jumped erratically. So did the world around her. This had happened before, but late at night when she was tired, never in the middle of the day. The light from the screen suddenly seemed too bright. And her headache, the one that was always present these days, tightened from a dull ache to a squeezing pressure on the back of her head and neck. Nearly in tears from pain and frustration, the 19-year-old called her mother. She couldn’t see; she couldn’t drive. Could her mother pick her up from work? The problems with her eyes began in grade school. Two years earlier, she nearly went blind. All she could see on the left was a rim of light. Everything else was blocked by a big black spot. And then a black dot appeared in her right eye as well. Her parents took her to see many eye doctors, only to be told that there was nothing wrong. One doctor told them that she had “emotional blindness.” The young woman’s vision somehow got a lot better on its own, and though the black dot still obstructed some of her vision, for the last eight months she’d been able to drive — so important in this small mountain town an hour north of San Diego. Now she couldn’t see for what seemed like a different reason. The young woman’s mother arranged for her to go to San Diego to see a neuro-ophthalmologist — a doctor who specializes in vision problems that originate in the brain. When they got to the office, though, the young woman’s vision and headache had returned to their imperfect but baseline state. She told the doctor that her symptoms were least intrusive in the morning; standing and walking seemed to make everything worse. Come back later, the doctor instructed. Mother and daughter walked around and shopped. When a couple of hours later the daughter’s eyes started jumping and her headache worsened, they hurried back to the office. © 2018 The New York Times Company

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 5: The Sensorimotor System
Link ID: 24946 - Posted: 05.07.2018

by Eli Rosenberg At least a dozen and a half people have been diagnosed with a rare form of eye cancer in two locations in North Carolina and Alabama, leaving medical experts mystified about the cause. Ocular melanoma occurs in about 6 out of every 1 million people, according to CBS News, and at least 18 people who have been diagnosed with the eye cancer have connections to Huntersville, N.C., Auburn, Ala., or both locations. Marlana Orloff, an oncologist at Thomas Jefferson University in Philadelphia, is studying the cases with her colleagues, according to CBS. “Most people don’t know anyone with this disease,” Orloff said. “We said, 'Okay, these girls were in this location, they were all definitively diagnosed with this very rare cancer — what’s going on?’ ” Alabama health officials have declined to call the outbreak a cluster yet. Three friends, Juleigh Green, Allison Allred and Ashley McCrary, are among those who have been treated for the cancer, and two of them, Green and Allred, had to get an eye removed. “What’s crazy is literally standing there, I was like, ‘Well, I know two people who’ve had this cancer,’ ” McCrary said. Many of the patients are now traveling to Philadelphia for treatment. The cancer has presented complications for some of the patients, CBS reported. Lori Lee, an Auburn University graduate, had the cancer metastasize in her liver. © 1996-2018 The Washington Post

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24926 - Posted: 05.01.2018

Jaclyn was diagnosed with myopia, or nearsightedness, at the age of age four. "I was surprised to learn that she needed glasses," recalled her mother, Ellen Rosenberg, in Toronto. Jaclyn wears glasses all the time at school, where they help her to read and write, she said. Her vision isn't so poor that she trips on things when she takes them off to play sports, Rosenberg said. But in a recent study, more than 30 per cent of young Canadian children walked around with fuzzy vision because of myopia that, unlike Jaclyn's, went undiagnosed. Now experts are exploring a simple way to turn the tide on the worsening problem. Myopia is "increasing globally at an alarming rate," according to the World Health Organization. It affects an estimated 1.89 billion people worldwide, and if rates don't change, that could rise to 2.56 billion by 2020 — a third of the population. Research suggests spending time outdoors protects against myopia. (Pond5) In what they call the first study of its kind in Canada, optometrists in Waterloo, Ont., found the rate of myopia was six per cent in children aged 6 to 8. That soared to 28.9 per cent in children aged 11 to 13. In myopia or nearsightedness, the eyeball doesn't get enough light and elongates. The condition isn't innocuous, said study author Debbie Jones, a clinical professor of optometry at the University of Waterloo and a scientist at the Centre for Ocular Research & Education. ©2018 CBC/Radio-Canada.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 13: Memory, Learning, and Development
Link ID: 24884 - Posted: 04.21.2018

Omega-3 fatty acid supplements taken orally proved no better than placebo at relieving symptoms or signs of dry eye, according to the findings of a well-controlled trial funded by the National Eye Institute (NEI), part of the National Institutes of Health. Dry eye disease occurs when the film that coats the eye no longer maintains a healthy ocular surface, which can lead to discomfort and visual impairment. The condition affects an estimated 14 percent of adults in the United States. The paper was published online April 13 in the New England Journal of Medicine. Annual sales of fish- and animal-derived supplements amount to more than a $1-billion market in the United States, according to the Nutrition Business Journal. Many formulations are sold over-the-counter, while others require a prescription or are available for purchase from a health care provider. “The trial provides the most reliable and generalizable evidence thus far on omega-3 supplementation for dry eye disease,” said Maryann Redford, D.D.S., M.P.H., program officer for clinical research at NEI. Despite insufficient evidence establishing the effectiveness of omega-3s, clinicians and their patients have been inclined to try the supplements for a variety of conditions with inflammatory components, including dry eye. “This well-controlled investigation conducted by the independently-led Dry Eye Assessment and Management (DREAM) Research Group shows that omega-3 supplements are no better than placebo for typical patients who suffer from dry eye.” The 27-center trial enrolled 535 participants with at least a six-month history of moderate to severe dry eye. Among them, 349 people were randomly assigned to receive 3 grams daily of fish-derived omega-3 fatty acids in five capsules.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24868 - Posted: 04.16.2018

By Anna Azvolinsky In recent years, scientists have accomplished what previously was saved for miracle workers: they have given blind patients the ability to see better. In 2017, the vision field saw an enormous advance with the approval Luxturna, the first gene therapy to correct vision loss in certain patients with childhood onset blindness. And just last week, researchers reported that a retinal implant allowed a 69-year-old woman with macular degeneration to more than double the number of letters she could identify on a vision chart. “It’s early data but very promising, including one patient with impressive vision gains, for a disease where we don’t have any treatment options,” says Thomas Albini of the University of Miami’s Bascom Palmer Eye Institute who was not involved in the study. The implant, given to five patients with dry age-related macular degeneration (AMD), is a single sheet of retinal pigment epithelial (RPE) cells derived from human embryonic stem cells. Other teams across the globe are inventing their own form of RPE implants, and this type of approach is just one of a plethora of modalities being tested to either slow down or reverse various forms of blindness. © 1986-2018 The Scientist

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24858 - Posted: 04.12.2018

Phil Plait I've said this before and I will no doubt say it many times hence: I love optical illusions. For one thing, they're just fun. They warp our sense of reality, and it's really pretty cool to see how easy it is to fool our senses. Some illusions do this in complicated ways that make it hard to understand where our perception goes wrong (and yes, there are entire fields of psychology devoted to figuring out how our brain and eyes physically react to illusions). But others are surprisingly simple, yet are deeply difficult to not see. One of the best is the Müller-Lyer illusion, and the easiest way to describe it is to just show it to you: The two horizontal lines are the same length, but the lower one looks longer thanks to the Müller-Lyer illusion. The two horizontal lines are the same length, but the lower one looks longer thanks to the Müller-Lyer illusion. Despite what your eyes are telling you, those two horizontal lines are the same size! Measure them if you don't believe me. It's an utterly convincing illusion, but an illusion all the same. But still, it's simple, right? Well, visual artist Gianni Sarcone decided to play with this illusion, and created an animated version of it that is simply stunning.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24857 - Posted: 04.12.2018

By James Gallagher Doctors have taken a major step towards curing the most common form of blindness in the UK - age-related macular degeneration. Douglas Waters, 86, could not see out of his right eye, but "I can now read the newspaper" with it, he says. He was one of two patients given pioneering stem cell therapy at Moorfields Eye Hospital in London. Cells from a human embryo were grown into a patch that was delicately inserted into the back of the eye. Douglas, who is from London, developed severe age-related macular degeneration in his right eye three years ago. The macula is the part of the eye that allows you to see straight ahead - whether to recognise faces, watch TV or read a book. He says: "In the months before the operation my sight was really poor and I couldn't see anything out of my right eye. "It's brilliant what the team have done and I feel so lucky to have been given my sight back." The macula is made up of rods and cones that sense light and behind those are a layer of nourishing cells called the retinal pigment epithelium. When this support layer fails, it causes macular degeneration and blindness. Doctors have devised a way of building a new retinal pigment epithelium and surgically implanting it into the eye. The technique, published in Nature Biotechnology, starts with embryonic stem cells. These are a special type of cell that can become any other in the human body. © 2018 BBC.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 7: Vision: From Eye to Brain; Chapter 13: Memory, Learning, and Development
Link ID: 24772 - Posted: 03.20.2018

Jason Beaubien The blind have descended in droves on the Bisidimo Hospital in Eastern Ethiopia. The Himalayan Cataract Project is hosting a mass cataract surgery campaign at the medical compound that used to be a leper colony. For one week a team from the nonprofit has set up seven operating tables in four operating rooms and they're offering free cataract surgery to anyone who needs it. On the first day of the campaign it's clear that the need is great. "We have like 700 or 800 patients already in the compound and many more appointed for tomorrow and the day after and the day after that," says Teketel Mathiwos, the Ethiopian program coordinator for the Himalayan Cataract Project. People hoping to get their sight restored are jammed into the compound's main courtyard. Others spill out of an office where optometrists are prepping patients for surgery. The line to get into the actual operating theater extends all the way out of the building, up along a covered walkway and then loops around the corner of another medical building. More still are standing outside the hospital gates. Mathiwos says some patients may have to wait a day or two for the procedure. "They have tents here," Mathiwos says. "We give them the food to eat and we try to take care of them as best as we can." Some of the patients at the Bisidimo Hospital have only one milky eye. Others are blind in both eyes. These patients underwent surgery as part of a campaign run by Himalayan Cataract Project at the Bisidimo Hospital in Ethiopia. The bandages are removed the day after the procedure. Surgeons performed more than 1,600 cataract surgeries during a six-day event in December. © 2018 npr

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24688 - Posted: 02.22.2018

By Susana Martinez-Conde The latest illusion to go viral in social media depicts two side-by-side stretches of a narrow road, receding in the distance. Both images depict the retreating road at an oblique angle, but the right road’s slant is a lot more pronounced than the slant on the left road. These are two identical photos of a road in Mexico. Credit: Daniel Picon Or is it? In fact, both pictures are identical. As user djeclipz put it, upon sharing the soon-to-become global sensation on Reddit: “This is the same photo, side by side. They are not taken at different angles. Both sides are the same, pixel for pixel.” Advertisement So why do they look so different? The illusion, created in 2010 by the French artist Daniel Picon and entitled “Roads in Mexico,” is a powerful variant of an earlier perceptual phenomenon discovered in 2007 by vision scientists Frederick Kingdom, Ali Yoonessi, and Elena Gheorghiu (all of them then at McGill University). Kingdom and his colleagues dubbed the effect the “Leaning Tower Illusion,” because they first noticed it in a pair of identical photos of the Leaning Tower of Pisa. But, as Kingdom, Yoonesi, and Gheorghiu noted in an excellent Scholarpedia article about their discovery, “the illusion works with any image of a receding object,” including tram lines, train tracks and roads in Mexico. The Leaning Tower Illusion won First Prize in the 2007 Best Illusion of the Year Contest, and is featured prominently in our recent book about the annual competition, Champions of Illusion. An excerpt of Champions of Illusion follows, concerning the bases of this effect: © 2018 Scientific American,

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24646 - Posted: 02.12.2018

by Ben Guarino Praying mantises do not perceive the world as you and I do. For starters, they're not very brainy — they're insects. A human brain has 85 billion neurons; insects such as mantises have fewer than a million. But mantises, despite their neuronal drought, have devised a way to see in three dimensions. They have a unique sort of vision unlike the 3-D sight used by primates or any other known creature, scientists at the University of Newcastle in Britain discovered recently. The scientists say they hope to apply this visionary technique to robots, allowing relatively unintelligent machines to see in 3-D. “Praying mantises are really specialized visual predators,” said Vivek Nityananda, an animal behavior expert at the university's Institute of Neuroscience. They are ambush hunters, waiting in stillness to strike at movement. Yet unlike other insects, they have two large, forward-facing eyes — the very feature that enables vertebrates to sense depth. Previous research had suggested that praying mantises use 3-D vision, also called stereopsis. Stereo vision, Nityananda said, is “basically comparing the slightly different views of each eye to be able to work out how far things are from you.” Uncovering the particulars of mantis stereo vision required a lot of patience and a little beeswax. Luckily, Nityananda and his teammates had both. Using the beeswax like glue — in a way that did not harm the insects — they affixed lenses to their faces. The lenses, similar to old-fashioned 3-D movie glasses, had one blue filter paired with one green filter. The mantises then were placed in front of a screen — an insect cinema, the researchers called it. © 1996-2018 The Washington Post

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24636 - Posted: 02.09.2018

By Carly Ledbetter Two years after “the dress” divided people over its color, the internet is back with another puzzling wardrobe question. What color are these shoes? Some people think these Vans sneakers look gray and mint (or teal), while others see pink and white. For some, the color changes the more they stare at the shoes: While others are dead-set on the color they see: Twitter user @dolansmalik explained one theory about why the shoes look like different colors to some people: “THE REAL SHOE IS PINK & WHITE OKAY?!” she wrote on Twitter. “The second pic was with flash & darkened, so it looks teal & gray. (depends on what lighting ur in).” Bevil Conway is an investigator with the National Eye Institute who helped contribute to a study on the differences in color perception for the famous “dress” controversy two years ago. He told HuffPost how and why our eyes play tricks on us, in situations like “the dress” and the shoes above. “This is related to the famous dress insofar as both are related to issues of color constancy,” he explained. “Basically your visual system is constantly trying to color correct the images projected on the retina, to remove the color contamination introduced by the spectral bias in the light source.” Conway explained just how and why some people see turquoise in the shoes, while others see pink. “In that manipulated photograph there is a lot of the turquoise cast over the whole image. When you first look at it, after having looked at the pink version, your visual system is still adapted to the lighting conditions of the pink version and so you see the turquoise in the other version, and you attribute this to the shoe itself,” he said. “But after a while, your visual system adapts to the turquoise across the whole of that image and interprets it as part of the light source, eventually discounting it and restoring the shoe to the original pink version (or at least pinker).” ©2018 Oath Inc.

Related chapters from BN8e: Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 7: Vision: From Eye to Brain
Link ID: 24575 - Posted: 01.26.2018