20-20-20 rule combats eye strain, blue light 

Students and adults alike spend an exponentially greater amount of time peering over their phones, tablets, computer screens and television sets than even ten years ago. With this in mind, researchers and others concerned throughout world have begun questioning and testing the potential effects of the screen light on our eyesight.

Unfortunately, this is a relatively new area of study and much remains to be discovered regarding the effects, especially long-term. Therefore, a bulk of the ideas are theories, waiting to be proved or rejected.

Ophthalmologist Dr. Samuel Hinton works at EYE-Q Vision Care in Fresno and addresses some of the chief concerns.

“The phones and tablets in themselves aren’t bad for your eyes,” Hinton said. “Any time you use something for a long period of time, a tablet, a phone, a computer, reading, watching TV, you tend to strain them a little bit because you don’t blink as much as we would otherwise when were focusing on doing some specific task. There is some concern that blue light (HEV) can cause some damage to the eyes but that’s been debated back and forth. Blue light, low spectrum light, has a chance of causing long-term damage but the jury is still out there whether it does or not.”

Blue light, high-energy visible light (HEV), is high-frequency, high-energy light in the violet/blue band in the visible spectrum. Although not confirmed, blue light has been suggested as a cause of accelerated macular degeneration. Still, some studies on animals showed high amounts of HEV light damaged retinal tissues.

The strain usually affects the surface of the eyes. Because we don’t blink as much the eyes don’t get lubricated and they dry out a little bit. The 20-20-20 rule says, for every 20 minutes of screen activity, you should take a 20 second break and look 20 feet away and blink your eyes to give them a chance to recover. The main issue is on the surface, coined Computer Vision Syndrome. As far as the possibility of the blue light being an issue, the theory is it could cause damage in the retina, leading to early Macular Degeneration. — Dr. Samuel Hinton, Ophthalmologist

The HEV light messes with the internal circadian rhythm, your biological sleep cycle, by simulating the same HEV light as the sun.

However, the damage comes from straining your eyes. Studies show people blink less when focusing on a screen or book than when going about their normal activities. Hinton explains how to eliminate this issue.

“The strain usually affects the surface of the eyes,” Hinton said. “Because we don’t blink as much the eyes don’t get lubricated and they dry out a little bit. The 20-20-20 rule says, for every 20 minutes of screen activity, you should take a 20 second break and look 20 feet away and blink your eyes to give them a chance to recover. The main issue is on the surface, coined Computer Vision Syndrome. As far as the possibility of the blue light being an issue, the theory is it could cause damage in the retina, leading to early Macular Degeneration.”

Computer Vision Syndrome symptoms include headaches, blurred vision, dry eyes, neck and shoulder pain. Causes include poor lighting, glare on a digital screen, improper viewing distances, poor sitting posture and uncorrected vision problems.

The 20-20-20 rule is a tactical way to defend your eyes against strain. Hinton discusses some other options to help keep your eyes and body healthy.  

“Most of our phones have a night mode on them that they switch into,” Hinton said. “That has more to do with having less blue light to simulate daylight to help your circadian rhythm. You want to hold the screen as far away as you can where it is still easily readable, you don’t want to hold it up close to your face if you don’t have to. If you keep the screen right at eye level or below, that’s helpful because that is our usual reading level. Looking up is a strain on our eyes because we don’t usually use our muscles to look up. The closer you hold the tablet, the more your eyes are focusing and therefore straining.”

The grayscale mode also provides a way to potentially protect your eyes from strain by resting the rod cells in your eyes. This is not confirmed and Hinton believes it makes no difference. 

“Grayscale would be affecting the rods of your eyes,” Dr. Hinton said. “There’s two kinds of cells in the eye. The rods do the color and the cones do black and white. Cones are more located in the center part of your vision so that’s where you get your crisp vision from. The rods are more on the outside. Your cones can see better because they’re closer packed together, but the rods do a better job of picking up minute light so you could theoretically have less light on the grayscale mode, but I don’t think it makes any difference.”

Sophomore Avery Jones attests to the symptoms from straining her eyes. She finds it occurs most when completing homework.

“It doesn’t happen everyday, but when I look at my computer or phone for a long time I can feel my eyes start to burn,” Jones said. “It usually happens at night or when I am super tired, probably because I am looking at a small screen up close which I don’t think is good for my eyes.”

The 20-20-20 rule limits strain on your eyes, giving them rest. Night mode on phones and computers is a great way to block conceivable blue light damage and keep your body’s biological clock on time. 

Aware of the hidden dangers of screen time? These strategies can help reduce exposure in today’s digital age: https://t.co/VDG7owYzjl @BCBSM pic.twitter.com/krtDtNptql

— Visiant (@VisiantHealth) April 3, 2017

It remains difficult to understand the long-term effects potentially caused by blue light, eye strain and other unknown ailments. The iPhone came out only eleven years ago so only time and research will tell as younger generations grow up with screens found everywhere you look.

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This author can be reached via twitter @alexrurik23 and via email: Alexander Rurik.