June 13, 2014 | POSTED BY | Clinical Optometry, Events
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It’s relatively common knowledge that “blue light” is harmful to your eyes. If you didn’t know, now you do. It doesn’t necessarily have to be “blue” to be harmful. Imagine the difference between an old-school incandescent bulb and a high powered fluorescent lightbulb. Which is easier to look at? Chances are you’ll prefer the warm glow of the incandescent. While the EPA may prefer (and even mandate) we phase out these sources of light in favor of more energy-efficient compact fluorescent bulbs (also known as CFL’s), these lights can cause eyestrain and insomnia among other conditions.

Computer Vision Syndrome

Turns out that women in the 70’s had the right idea when they started wearing rose-tinted lenses in the office. Rose-tinted lenses decrease the absorption of the blue tinted light from the fluorescent overhead light and they claim it eased their eyes. When computers came onto the scene, sitting in front of one for hours on end was eased more so by these lenses – but they have somewhat fallen out of fashion. Now millions of Americans suffer from eyestrain at the office-also known as Computer Vision Syndrome (CVS). CVS is a collection of symptoms many people, many presbyopes, experience during the day-often eyestrain, dry eyediplopia, and headaches.

Where the problem lies is that very few people turn off their computers when they leave the office. More and more people are not only working longer hours, they aren’t unplugging after hours. Ipads and cell phones are glued 8 inches from our faces for longer and longer stretches of time, and younger and younger people are becoming increasingly exposed to the false blue-white wavelengths emitted from all the electronics we’re constantly glued to. It’s not uncommon to see a two year old on an Ipad or a ten year old texting away for hours. Electronics in children can increase binocular vision problems on an already fragile developing system, so it’s even more vital to limit usage of devices varying on the child’s age.

Insomnia

Insomnia is a sleep disorder which plagues millions of adults. Acute insomnia is a short term inability to sleep which can last for a few days to a few weeks. It can involve inability to fall asleep, stay asleep, or wake feeling rested. Chronic insomnia usually lasts for longer periods of time and fatigues the person chronically. The theory is that blue-white light stimulates the brain to stay awake and alert, since blue-white light is what is emitted at the peak of noon when the sun is high in the sky and the sky is blue. When we stare at our devices late into the night, we trick our brain into thinking it’s still midday. Melatonin (a hormone signaling it’s time for sleep) isn’t released, and we find it difficult to fall asleep. Even having the TV on or a blue alarm clock in the background can be stimulating for some individuals. On the other side of the coin, yellow white light (similar to incandescent light) mocks what light we would see as the sun is naturally setting. It’s reddish in hue and soft. It lets our brain know it’s time to relax and sleep. This is why we often feel calmer with this “hue of white”. Using candles has a similar effect.

To counter the effects of the blue-white light, unplug as many electronics 1 hour before bedtime. This will help signal to the brain that it’s time to shut off and sleep. In addition, if a computer must be used in the later hours of the evening, a free program called f.lux can be downloaded which helps decrease the blue light emitted from the monitor. It contains a timetable of the sunsets and rises and dims the screen upon sunset. In addition, a pair of blue-blocker glasses (amber in color) can be purchased from your optometrist or even a sporting goods store or Amazon and are inexpensive. The tint on these lenses are similar to the rose in the example from the 70’s: they absorb the blue light in the tint so that little to no blue light can reach the cornea. The combination of decreasing usage, f.lux, and blue-blockers can be effective in decreasing eyestrain at night and serving as non-medicinal insomnia remedies.

AMD Risk

Even more harmful still than insomnia or strain is the potential for retinal disease later on. Research has shown that increased exposure to blue light over extended periods of time can increase the risk for AMD. Not much research exists yet, since the technological age boomed 20-25 years ago, and the target population has not had enough time to age into the target range. However, blue light has the shortest wavelength over any visible wavelength and is the most potentially damaging light to the retina (second to UV, which is invisible). When the retina absorbs excessive blue light over a lifetime, the retinal cells can’t handle the high energy waves anymore and the retina begins to deteriorate. Antioxidants are promising as prevention for AMD, but no treatment to reverse retinal damage exists.

Make sure EVERYONE you know is wearing sunglasses that are UV protected. Polarized are obviously the best option as they block glare and UV, but UV is absolutely essential. Without it (with just a dark tint), the pupil actually DILATES behind the dark lens, and without UV protection, the retina absorbs more radiation than it would without sunglasses on! In patients at risk or with early AMD, talk to your optometrist about antioxidants and supplements to decrease the risk of retinal damage.