Blue light blocking glasses not reccomended by AAO

Blue light filtering glasses have become increasingly popular during the digital age. Touted as protection against screen-induced eye damage, the glasses have become widely available. Harvard Medical School said that most commercially available blue light filtering glasses and prescription lens coatings are not standardized, so there is no way to know which light waves are actually being filtered. 

Screen-induced eye damage comes from how people are using screens, not the light emitted from the screens, according to the AAO. 

Hours spent staring at screens can cause reduced blinking. Less blinking can lead to dry eyes and other symptoms of eye strain, said the AAO. 

Role of blue light

During the day, blue light is beneficial to alertness. It doesn’t only come from screens, but also from the sun. 

At night, however, any form of light can mess with our circadian rhythm. 

Blue light, according to researchers, has a higher impact on melatonin production. Melatonin is a hormone naturally secreted by our brains, and it helps us fall asleep. Blue light suppresses melatonin production, making it more difficult to fall asleep if exposed too close to bedtime.

Harvard researchers conducted an experiment to measure the impacts of blue light. All subjects were exposed to six and a half hours of different colored light. One group experienced green light and the other blue. Green light suppressed melatonin production in the subjects for about an hour and a half. The blue light suppressed the secretion of the hormone for double the amount of time, or three hours, having a greater impact on the subjects’ ability to fall asleep. 

Lack of adequate sleep can cause health problems such as depression, diabetes, and stroke, according to the National Institute of Health.

Avoiding eye strain 

Digital eye strain can be avoided in a few ways, according to the AAO. 

First, sit about 25 inches, or an arm’s length away from computer screens. Position them so that your gaze is tilted slightly downward. 

Second, the AAO recommends taking breaks using the 20-20-20 rule: “every 20 minutes, shift your eyes to look at an object at least 20 feet away for at least 20 seconds.”

Third, if your eyes are feeling dry, use artificial tears to moisten them. If you wear contact lenses, give your eyes a break and switch to glasses sometimes. 

Finally, adjust the lighting in your work environment and increase the contrast on your computer screen. A matte screen filter might also be helpful in reducing digital eye strain. 

Avoiding circadian rhythm impacts

To avoid overstimulation caused by blue light, minimize your screen usage between two and three hours before you plan to go to sleep, said Harvard. 

If screen usage during that time is necessary, consider using software that can filter out blue light. Apple devices come equipped with Night Shift, which adjusts color tones to be warmer. An alternative is f.lux, which is available on all computers. 

Harvard also recommends getting as much exposure to daylight as possible. Exposure to daylight can help provide a strong stimulation to the circadian rhythm. 

Related reading:

• New study: excessive screen time can stunt child development
• A night owl may have unhealthy habits that lead to early death, study says
• Can you change from a night owl to an early bird? Here’s what sleep experts think