If you were ever scolded as a child for reading in the dark, or if you wore blue-blocking glasses while working on a computer, you may have incorrect ideas about eye health.
About four out of 10 adults in the United States are at high risk for vision loss, according to the Centers for Disease Control and Prevention. But many eye conditions can be treated or prevented, said Dr. Joshua Ehrlich, an assistant professor of ophthalmology and visual sciences at the University of Michigan.
Here are nine common beliefs people have about eye health, and what the experts have to say about it.
Reading a book or looking closely at an electronic device is bad for your eyes.
TRUE. Our eyes are not meant to focus on objects close to our face for long periods of time, said Dr. Xiaoying Zhu, clinical associate professor of optometry and principal investigator of myopia at SUNY College of Optometry in New York City. When we do it, especially when we are children, it favors the eyeball to elongate, which over time can cause nearsightedness or nearsightedness.
To help reduce the strain on your eyes, Dr. Zhu recommends following the 20-20-20 rule: After 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.
FAKE. However, if the lighting is so dim that you need to hold your book or tablet close to your face, that can increase the risks mentioned above and create eyestrain, which can cause pain around the eyes and temples, headaches and difficult to focus. But these are usually temporary symptoms, Dr. Zhu said.
Spending more time outdoors helps your eyesight.
TRUE. some research (focused mainly on children) suggests that time outdoors may reduce the risk of developing myopia, said Maria Liu, an associate professor of clinical optometry at the University of California, Berkeley. Experts don’t fully understand why this happens, but some research suggests that bright sunlight can animate the retina to produce dopaminethat discourages the elongation of the eyes (although these experiments have been done mainly with animalssaid Dr. Zhu).
Too much ultraviolet light can damage your eyesight.
TRUE. There’s a reason experts say you shouldn’t look at the sun. Too much exposure to ultraviolet A and B rays in sunlight can “cause irreversible damage” to the retina, Dr. Ehrlich said. This can also increase your risk of developing cataracts, he said.
Too much exposure to ultraviolet light can also increase the risk of developing cancers in the eyesaid Dr. Ehrlich, although this risk is low. Wearing sunglasses, glasses or contact lenses that block UV rays can offer protection.
Taking a break from wearing glasses can prevent your vision from getting worse.
FAKE. Some patients who need glasses tell Safal Khanal, an assistant professor of optometry and vision sciences at the University of Alabama at Birmingham, that they don’t wear glasses all the time because they believe they will worsen their condition. “That’s not true,” he said. If you need glasses, you must wear them.
Even a little blue light from screens is harmful to the eyes.
FAKE. While some research has found that exposure to blue light can damage the retina and potentially cause vision problems over time, no strong evidence has confirmed that this happens with typical exposures in humans, Dr. Ehrlich said. There’s also no evidence that wearing blue-blocking glasses will improve eye health, he added.
But screens can be bad for your eyes in other ways described above, including by causing dry eyes, Dr. Zhu said. “When we look at a screen, we just don’t blink as often as we should,” he said, and that can cause eyestrain and temporary blurred vision.
Smoking is bad for eye health.
TRUE. TO 2011 CDC study linked smoking with self-reported age-related eye diseases in older adults, including cataracts and age-related macular degeneration, a disease in which part of the retina breaks off and blurs vision. Toxic chemicals in cigarettes enter the bloodstream and damage sensitive tissues in the eyes, including the retina, lens and macula, Dr. Khanal said.
Carrots are good for the eyes.
TRUE. While a diet full of carrots won’t give you perfect vision, some evidence suggests that the nutrients they contain are good for eye health. One large clinical trialfor example, it found that supplements containing nutrients found in carrots, including antioxidants such as beta-carotene and vitamins C and E, could slow the progression of age-related macular degeneration.
Eating a diet rich in antioxidants won’t necessarily prevent eye disease from occurring, but it may be helpful “particularly for people with early macular degeneration,” Dr. Ehrlich said.
The deterioration of vision is an inevitable part of aging.
FAKE. Most causes of vision decline in adulthood, including age-related macular degeneration, cataracts and glaucoma, can be prevented or treated if detected early, Dr. Ehrlich said. If his vision is starting to slip, don’t write it off as “just aging,” he added. Seeing an optometrist or ophthalmologist right away (or regularly, every year) will give you the best chance of avoiding these conditions, he said.