The average American adult spends somewhere around nine hours a day looking at a screen. Children up to 8 years old are averaging two hours, while 8- to 10-year-olds are averaging around six hours, and 11- to 18-year-olds come in around seven or eight hours.
Technology has brought us so far in many aspects, but there are many detrimental effects that we tend to overlook.
The past 20 years have brought lots of research on what these effects are. Beyond the toll it takes on your body to sit behind a computer for eight hours straight, what happens at the physiologic level in the eye?
“Blue light” that is emitted from your computers, smartphones and other screens is on the shorter wavelength but higher energy end of the spectrum of visible light. That means that this light can penetrate farther into the eye as less of it gets absorbed or blocked by the cornea and lens in the front of the eye.
Studies have shown that intense blue light exposure triggers cellular damage in the photoreceptor cells of the retina in a similar mechanism that we see cellular damage happen in macular degeneration.
A deeper look at the studies show that these results were found in a laboratory setting, but not in actual living tissue (the human eye). Furthermore, this damage occurred at blue light intensities far beyond the threshold for our digital devices.
This intensity is what we get from natural sunlight, and is why we recommend UV-A and UV-B sun protection outside.
So, am I advocating for us all to stare at screen as long as we want? Absolutely not!
From an ocular health standpoint, we do see a lot of over-focusing of the eye muscles from increased screen time and a huge increase in dry eye disease.
Additionally, blue light exposure before bedtime has shown to disrupt the body’s circadian rhythm and results in longer time to fall asleep, plus less REM sleep.
Researchers in Spain also recently published a study showing an increased risk of hormone dependent prostate and breast cancer in people who had higher exposure to artificial light at night.
While I do not think the research is conclusive enough for me to tell my patients that they need to put a blue light blocker into their glasses lenses (from an ocular health standpoint), it can’t hurt and does help with eye strain.
At the end of the day, we could all stand to put our devices away more frequently and enjoy the people and beauty around us.
Caroline Bundrick, O.D. is an optometrist practicing at Darling Eye Center, with offices in Bluffton and on Hilton Head Island.
