Fact Checked August 24, 2018
Too much screen time can wreck your eyes.
Smart phones, laptops, and other handheld devices all transmit light. However, the blue light in particular may be toxic for your eyes.
Scientists at the University of Toledo may have discovered how blue light emitted from your technology has a potential to lead to macular degeneration — one of the leading causes of vision loss in the United States.
“It’s no secret that blue light harms our vision by damaging the eye’s retina” said Ajith Karunarathne, PhD, assistant professor at the University of Toledo’s department of chemistry and biochemistry in a released statement.
Macular degeneration is the result of photoreceptor cell death in the retina.
The function of the photoreceptor cells is to capture visual images and signal them to the brain using a molecule called retinal.
Retinal, which is produced by the eye, is triggered by blue light and causes various chemical reactions. These reactions within the eye can be poisonous to the photoreceptor cell molecules rendering them damaged.
When these photoreceptor cells die, there’s no regeneration.
What did the study find?
Karunarathne and his team also introduced retinal to other cells in the body including heart cells, cancer cells, and neurons. When these retinal-infused cells were exposed to blue light they also died.
No change was seen when either blue light or retinal were used alone.
The team also exposed various cells throughout the body to green, yellow, and red light — and interestingly, no results were seen.
“The retinal-generated toxicity by blue light is universal. It can kill any cell type,” said Karunarathne.
Part of this phenomenon may be because blue light has a shorter wavelength in comparison to other colors, and as a result, has more energy. The extra energy can be the reason for this chemical change causing retinal-generated toxicity.
“Blue light appears to damage retinal cells. It is still unclear how much blue light and for how long it’s necessary to damage these sight-seeing cells. We do know the damage is irreversible,” said Dr. Mark Fromer, ophthalmologist at Lenox Hill Hospital in New York City.
Don’t freak out just yet. Despite the discovery that the combination of blue light and retinal can damage cells, the experiments were conducted in a laboratory setting, not on eyes themselves.
Karunarathne and his team conducted the study to understand the mechanism and ability to which blue light causes cell death — they’re unsure if this occurs in the eye itself.
In a statement on his university web site, Karunarathne states, “We caution the public that our study does not show that light from mobile devises or other digital screens cause blindness.”
He continues, “Whether blue light from mobile devises and digital screens induces similar toxicity levels is an unanswered question and is currently under investigation.”
Although age-related macular degeneration affects people of all ages, it’s most likely to occur after age 60. However, experts suspect this may come sooner with the increased use of blue light technologies.
According to the BrightFocus Foundation, as many as 11 million U.S. people currently have some form of age-related macular degeneration. This number is expected to reach 22 million by 2050.
Worldwide, they expect it to affect almost 288 million people by 2040.
Protecting yourself may seem as easy as avoiding blue light — but it may not be that straightforward.
Not only does blue light come from our digital devices, it also comes from natural sunlight.
Also, certain situations such as using your technology at night can intensify the blue light as well. Transmitted blue light, especially in the dark, channels the light into a very small area inside of your eye.
One study author relates this phenomenon to using a magnifying glass in the sun — the light can become so intense and focused that it can burn your eye.
The blue light from these screened devices can also lead to dry eyes.
“Studies have found that with the increased usage of smart phones, iPads, and laptops, there has been an increase in the development of dry eyes due to a decreased blink rate,” explains Angela Bevels, OD, founder and owner of Elite Dry Eye Spa in Tucson, Arizona.
Over time, the more someone engages with their devices the less they blink.
“This in effect causes the tears to evaporate faster, leaving the cornea to dry out,” says Bevels.
To help fight this phenomenon, several technology companies have already created potential solutions.
Apple currently offers the “night shift” setting and Samsung offers a “blue light filter” to decrease the amount of blue light that’s displayed on the screen of the device.
Fromer recommends that people should “consider decreasing your time on these devices” and to “give your eyes a rest if performing extensive tasks on the computer.”
He recommends simply closing one’s eyes for a short time or gazing into the distance to help relax the muscle of the eye and reduce unnecessary strain.
Although this study is good information for those who are at risk of degenerative eye conditions, it’s yet another reason for everyone else to consider limiting their exposure to the screens — especially after sunset.