Recently, eyecare professionals have been seeing patients increasingly worried about their family’s eye health due to their constant use of digital devices. Just how dangerous is blue light and how can you protect yourself and your family from it? “Blue light, high-energy wavelengths of light between 420 and 480 nm on the visible light spectrum can be both beneficial and harmful. Naturally contained within the full spectrum of visible and invisible (ultraviolet) rays of sunlight we experience daily, blue light helps suppress the body’s melatonin production for boosting general alertness and awareness during the day1.” Because blue light is so close to ultraviolet (UV) light in the spectrum, many people are concerned that their eyes will be more prone to the same negative effects that UV light has on the eyes, such as cataracts and macular degeneration. Because of the way they are made, the LED lights in digital screens emit artificial blue light, and many people can already feel the effects of increased screen time in the form of eyestrain or headaches.
Now that you know about what blue light is, you should know how it affects the eyes. Well, that is where things become a bit complicated. While it is true that blue light can damage the eye, research has not been able to show a negative effect on the health of the eye. The only measured effect of artificial blue light in adults is decreasing melatonin levels, which delays sleep in people who use devices before bed. Eye strain is still a common finding in people who use digital devices frequently, but that usually stems from an inability to focus up close (accommodate) or prolonged time accommodating, instead of blue light. Other frequent findings like dry eye can be attributed to a lack of blinking while using devices. In other words, the best way to protect your eyes during screen time is to take breaks and let your eyes rest for a few minutes. In general, a good rule to follow is 20-20-20: for every 20 minutes of screen time, take a 20 second break to look at something 20 feet away. As for why some people experience relief from “blue blocking glasses,” the answer is up for debate. While I would never prescribe blue blockers for computer use, I do acknowledge that some people genuinely find comfort in them for one reason or another, however they are not necessary by any means. For those who are truly worried about blue light, you should consider investing in a quality pair of sunglasses, since the sun is the greatest source of blue light that we have, and it actually can damage your eyes1.
In children, however, screens can have a much more profound effect. One study conducted in Canada found that children who have more than two hours of screen time per day were eight times more likely to have ADHD than children with less screen time. Increased screen time in children has also been linked to childhood obesity and increased incidence of nearsightedness. The American academy of Pediatrics recommends NO screen time for children under 2 years old and only one hour of screen time for children 2-5 years old2. These guidelines, followed up with annual eye exams, can help ensure that your children’s eyes are healthy and developing properly. Overall, blue light is not as serious of a threat as we are meant to believe, but screen use can still be detrimental to the development of children. Make them go outside and it will benefit them more than any blue filter could.
- “Blue-Light hype or much ado about nothing?” American Optometric Association. July 11, 2019. https://www.aoa.org/news/clinical-eye-care/health-and-wellness/blue-light-hype-or-much-ado-about-nothing?sso=y
- Porter, Daniel. “Blue Light and Digital Eye Strain.” American Academy of Ophthalmology. Dec 10, 2020. https://www.aao.org/eye-health/tips-prevention/blue-light-digital-eye-strain