EYE HEALTH IN THE DIGITAL AGE
Protect your eyes against blue light emitted from computers, cell phones, and other devices
light is the portion of the visible spectrum that, when isolated from other wavelengths of light, appears blue. e blue wavelengths, however, can mix with other wavelengths of light to produce di erent colors—sort of like mixing paint. For example, the bright and clear white background on your smartphone, tablet, or computer is produced by mixing yellow light with a strong blue light component. You see white, but there is a lot of blue reaching your eyes.
Why is this an issue? e portion of the spectrum that we see as blue has significantly higher energy than wavelengths corresponding to green, yellow, or red. Over time, this higher energy has the potential to overwork the retina (the light-sensitive neural tissue in the back of the eye), produce excessive unstable oxygen (i.e., free radicals), and ultimately damage the retina and lead to all sorts of other issues. Once the photoreceptor neurons in the retina are damaged or die, they cannot be repaired or regenerated.
Cell death is the worstcase scenario. But there are several other health-related issues that arise from exposure to excessive blue light, especially long-term exposure from screens. ese issues include eyestrain, eye fatigue, headache, neck strain, blurry vision, and reduced sleep quality. e incidence of these complaints is so high these days that there is now a condition called Computer Vision Syndrome (CVS) that consoli- dates these symptoms under one diagnostic umbrella.
Most digital devices made today mix blue light with yellow to produce a rich, vivid white color appearance. Studies show that blue light is the most capable of making a person squint their eyes because of discomfort. It would appear, therefore, that several of the symptoms of CVS may be produced from long-term (more than 4 hours a day) low-level squinting of the eyes. Squinting can produce eyestrain and eye fatigue, and can lead to tension headaches.
So, what can we do to reduce the negative outcomes associated with excessive blue light exposure from screens? Surprisingly, your diet can make a huge di erence. Specific nutrients called lutein and zeaxanthin, which are found primarily in leafy-green vegetables and other colored fruits and vegetables, are found in high concentrations in the retina, where they serve two very important functions:
. ey are extremely potent antioxidants, which enables them to protect the retina from damage, and . By virtue of their yellow color, lutein and zeaxanthin absorb blue light before it reaches the retina. Taken together, these nutrients protect the retina and reduce the chance of developing several symptoms of CVS.
Research shows that after six months of lutein and zeaxanthin supplementation, there were significant improvements in visual performance, eyestrain, eye fatigue, visual performance in bright light conditions, and sleep quality. A significant reduction in tension headache frequency was also noted with lutein and zeaxanthin supplementation. is study was placebo-controlled, and the subjects taking the placebo experienced none of these benefits. e supplements contained 20 mg lutein and 4 mg zeaxanthin, but lower doses have been found to make a di erence with long-term supplementation. Consistently consuming lutein and zeaxanthin appears to be the key, sending a message to your body that there is plenty circulating in the bloodstream, and that deposition in other tissues (e.g., the retina) can take place.
e dose used in the study noted above is equivalent to consuming about two bowls of spinach. Indeed, eating lots of leafy-green veggies and other colored fruits and vegetables will have the same e ects as those found with supplements.
e trouble is, most of us do not consume two bowls of spinach per day—certainly not on a consistent basis. In fact, the most recent data on the matter indicate that the average American adult consumes only about 1.5 mg of lutein daily. We are simply not eating enough healthy, colored fruits and veggies, and this prevents us from obtaining enough of these crucial nutrients.
Smartphones, tablets, and computer screens aren’t going away anytime soon. In an immediate sense, wearing special tinted lenses that screen out much of the blue light emitted by screens can help. Both contact and spectacle lenses have been developed for this purpose. Keep in mind, however, that lenses do not provide the antioxidant benefit to the retina, and they also tend to skew color vision. So, if what you are working on involves an accurate perception of color, lenses may not be the best choice.
e best long-term solution? Consumption of lutein and zeaxanthin, whether via diet or supplementation, is a proven way to improve eye health and reduce the incidence of CVS symptoms.
Given that the average American adult spends roughly 11 hours a day in front of screens, the availability of a safe, natural way to combat the potential for undesirable e ects is comforting.
Studies show that blue light is the most capable of making a person squint their eyes because of discomfort, and that squinting can produce eyestrain and eye fatigue, and lead to tension headaches.
did you 'now? The average American adult spends roughly 11 hours a day in front of screens.