It’s true that the rise in digital device use has led to concerns about exposure to blue light. While blue light is present in sunlight, prolonged exposure to artificial sources of blue light from device screens after dusk can affect sleep and circadian rhythms for some people.
However, Dr. Bryce St. Clair, an instructor in the Department of Ophthalmology at Johns Hopkins University, believes that the concern over blue light is exaggerated.
“Blue light, we know will signal your brain to stay more stimulated,” St. Clair pointed out. “Some people will say when they are on a phone or on a laptop before bed, that they stay awake longer than usual. And we know there’s evidence suggesting that it mildly affects circadian rhythms.”
St. Clair did note that prolonged device use can lead to reduced blinking, which may cause eye strain and dry eyes. He recommended that people who experience difficulty falling asleep use blue light blockers or night mode on their devices.
“There’s anecdotal evidence to suggest that if you are somehow involved with blue light devices, that you blink less often than those who don’t use blue light devices,” St. Clair noted.
However, St. Clair stressed that ultraviolet radiation from the sun is a primary concern for eye health. He advised wearing sunglasses outdoors to protect against UV radiation and UV damage to the eyes, which can cause cataracts and macular degeneration, as well as protect the eyelids against skin cancer. Experts recommend heavy users take periodic breaks from device screens by using the 20-20-20 rule, which is a 20-second break, every 20 minutes to look at something 20 feet away.
He recommended polarized sunglasses with UVA and UVB protection.
“Why are sunglasses fantastic? One, anytime you’re squinting because it’s too bright outside. That is your eye’s way of telling you that’s too much light. Number two, it prevents UV radiation and UV damage to the lens of your eye which can cause cataracts, to the retina which can cause macular degeneration,” St. Clair outlined.