If you were ever scolded as a child for reading in the dark, or if you wore blue-light blocking glasses while working on a computer, you may have incorrect ideas about eye health.
About 4 out of 10 adults in the US are at high risk of losing their eyesight, according to the US Centers for Disease Control and Prevention (CDC). But many eye diseases are treatable or preventable, according to Joshua Ehrlich, assistant professor of ophthalmology and visual sciences at the University of Michigan.
Here are nine common ideas people have about eye health and what experts have to say about them.
Looking at an electronic device up close is bad for your eyes.
True. Our eyes shouldn’t focus on objects close to the face for long periods of time, says Xiaoying Zhu, associate clinical professor of optometry and lead myopia researcher at the State University of New York. If we are in the habit, especially as children, we run the risk of stimulating the elongation of the eyeball, which over time can cause myopia, or difficulty seeing from afar.
To help reduce eye strain, Zhu recommends following the 20-20-20 rule: for every 20 minutes of close reading, look at something at least 20 feet away for at least 20 seconds.
Reading in the dark can make your eyesight worse.
False. However, if the lighting is so dim that you have to hold the book or tablet close to your face, it can increase the risks mentioned above and create eyestrain, which can lead to pain around your eyes and temples, headache and difficulty reading. concentration. But these symptoms are usually temporary, says Zhu.
Spending more time outdoors improves the view.
True. Some research (mostly focused on children) suggests that time outdoors can reduce the risk of developing nearsightedness, says Maria Liu, associate professor of clinical optometry at the University of California, Berkeley.
Experts don’t fully understand why this occurs, but some research suggests that bright sunlight may encourage the retina to produce dopamine, which discourages the eyes from elongating (although these experiments were mostly conducted with animals, Zhu points out).
Excessive ultraviolet light damages eyesight
True. There’s a reason experts say not to look at the sun. Excessive exposure to ultraviolet A and B rays in sunlight can “cause irreversible damage” to the retina, says Ehrlich. It can also increase your risk of developing cataracts, he says.
Too much exposure to UV light also increases your chances of developing eye cancer, says Ehrlich — although that risk is low. Wearing sunglasses, eyeglasses, or contact lenses that block UV rays can offer protection.
Not wearing your prescription glasses all the time prevents your condition from getting worse.
False. Some patients who need glasses tell Safal Khanal, an assistant professor of optometry and vision science at the University of Alabama at Birmingham, that they don’t wear glasses all the time because they think it will aggravate their condition. “Not true,” he says. If you need glasses, you must wear them.
Blue light, even a little, is harmful
False. While studies have found that blue light exposure can damage the retina and potentially cause vision problems over time, no solid evidence has confirmed that this happens with typical exposures in humans, Ehrlich points out. Nor is there any evidence that wearing blue light-filtering glasses improves eye health, he added.
But screens can impair vision in the other ways described above, including causing dry eyes, says Zhu. “When we look at a screen, we just don’t blink as often as we should,” she says, which can cause eyestrain and temporary blurred vision.
Smoking harms eye health
True. A 2011 CDC study linked smoking to age-related eye diseases in older adults, including cataracts and age-related macular degeneration, a disease in which part of the retina breaks down and blurs vision. Toxic chemicals from cigarettes enter the bloodstream and damage the eye’s sensitive tissues, including the retina, lens and macula, Khanal said.
Eating carrots is good for the eyes
True. While a diet full of carrots won’t give you perfect eyesight, some evidence suggests that their nutrients are good for eye health. A large clinical trial, for example, found that supplements containing nutrients found in carrots, including antioxidants like beta-carotene and vitamins C and E, can slow the progression of age-related macular degeneration.
Eating a diet high in antioxidants doesn’t necessarily prevent eye disease from occurring, but it can be helpful “especially for people with early macular degeneration,” says Ehrlich.
Worsening vision is an inevitable part of aging
False. Most causes of vision decline in adulthood — including age-related macular degeneration, cataracts and glaucoma — are preventable or treatable if caught early, Ehrlich points out. If his eyesight is starting to decline, don’t dismiss it as “just aging,” he adds.
Seeing an optometrist or ophthalmologist right away (or regularly, every year) will give you the best chance of avoiding these problems, he indicates.
Translated by Luiz Roberto M. Gonçalves