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Scientists May Have Found the Real Cause of Dyslexia—And a Way to Treat It

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Dyslexia is often described as trying to read letters as they jump around the page. Because of its connections to reading difficulties and trouble in school, the condition is often blamed on the brain. But according to a new study published in Proceedings of the Royal Society B, the so-called learning disability may actually start in the eyes.

As The Guardian reports, a team of French scientists say they've discovered a key physiological difference between the eyes of those with dyslexia and those without it. Our eyes have tiny light-receptor cells called rods and cones. The center of a region called the fovea is dominated by cones, which are also responsible for color perception.

Just as most of us have a dominant hand, most have a dominant eye too, which has more neural connections to the brain. The study of 60 people, divided evenly between those with dyslexia and those without, found that in the eyes of non-dyslexic people, the arrangement of the cones is asymmetrical: The dominant eye has a round, cone-free hole, while the other eye has an unevenly shaped hole. However, in people with dyslexia, both eyes have the same round hole. So when they're looking at something in front of them, such as a page in a book, their eyes perceive exact mirror images, which end up fighting for visual domination in the brain. This could explain why it's sometimes impossible for a dyslexic person to distinguish a "b" from a "d" or an "E" from a "3".

These results challenge previous research that connects dyslexia to cognitive abilities. In a study published earlier this year, people with the condition were found to have a harder time remembering musical notes, faces, and spoken words. In light of the new findings, it's unclear whether this is at the root of dyslexia or if growing up with vision-related reading difficulties affects brain plasticity.

If dyslexia does come down to some misarranged light-receptors in the eye, diagnosing the disorder could be as simple as giving an eye exam. The explanation could also make it easy to treat without invasive surgery. In the study, the authors describe using an LED lamp that blinks faster than the human eye can perceive to "cancel out" one of the mirror images perceived by dyslexic readers, leaving only one true image. The volunteers who read with it called it a "magic lamp." The researchers hope to further experiment with it to see see if it's a viable treatment option for the millions of people living with dyslexia.

[h/t The Guardian]

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'Lime Disease' Could Give You a Nasty Rash This Summer
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A cold Corona or virgin margarita is best enjoyed by the pool, but watch where you’re squeezing those limes. As Slate illustrates in a new video, there’s a lesser-known “lime disease,” and it can give you a nasty skin rash if you’re not careful.

When lime juice comes into contact with your skin and is then exposed to UV rays, it can cause a chemical reaction that results in phytophotodermatitis. It looks a little like a poison ivy reaction or sun poisoning, and some of the symptoms include redness, blistering, and inflammation. It’s the same reaction caused by a corrosive sap on the giant hogweed, an invasive weed that’s spreading throughout the U.S.

"Lime disease" may sound random, but it’s a lot more common than you might think. Dermatologist Barry D. Goldman tells Slate he sees cases of the skin condition almost daily in the summer. Some people have even reported receiving second-degree burns as a result of the citric acid from lime juice. According to the Mayo Clinic, the chemical that causes phytophotodermatitis can also be found in wild parsnip, wild dill, wild parsley, buttercups, and other citrus fruits.

To play it safe, keep your limes confined to the great indoors or wash your hands with soap after handling the fruit. You can learn more about phytophotodermatitis by checking out Slate’s video below.

[h/t Slate]

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Why Eating From a Smaller Plate Might Not Be an Effective Dieting Trick 
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It might be time to rewrite the diet books. Israeli psychologists have cast doubt on the widespread belief that eating from smaller plates helps you control food portions and feel fuller, Scientific American reports.

Past studies have shown that this mind trick, called the Delboeuf illusion, influences the amount of food that people eat. In one 2012 study, participants who were given larger bowls ended up eating more soup overall than those given smaller bowls.

However, researchers from Ben-Gurion University in Negev, Israel, concluded in a study published in the journal Appetite that the effectiveness of the illusion depends on how empty your stomach is. The team of scientists studied two groups of participants: one that ate three hours before the experiment, and another that ate one hour prior. When participants were shown images of pizzas on serving trays of varying sizes, the group that hadn’t eaten in several hours was more accurate in assessing the size of pizzas. In other words, the hungrier they were, the less likely they were to be fooled by the different trays.

However, both groups were equally tricked by the illusion when they were asked to estimate the size of non-food objects, such as black circles inside of white circles and hubcaps within tires. Researchers say this demonstrates that motivational factors, like appetite, affects how we perceive food. The findings also dovetail with the results of an earlier study, which concluded that overweight people are less likely to fall for the illusion than people of a normal weight.

So go ahead and get a large plate every now and then. At the very least, it may save you a second trip to the buffet table.

[h/t Scientific American]

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