Smartphones, tablets, computers, high-definition TVs—there’s no doubt we love our digital devices. In many ways, technology makes life easier. How else could you go shopping from the comfort of your own couch? Americans devote more than 10 hours a day to screen time according to Nielsen, but there’s mounting evidence that it can have serious health consequences.

Like many teenagers, Luke Farias spends at least five hours a day on his phone and a couple more hours watching TV.

“It’s hard to tell yourself no,” said the 16-year-old high school sophomore.

For years he’s been dealing with symptoms of dry eye disease, a chronic and progressive inflammation of the ocular surface, which can happen when the eye doesn’t produce the right quantity or quality of tears.

“It burns and there’s an urge to itch and rub my eyes, especially indoors in cold areas. It’s frustrating. I feel like I’m the only one who feels this pain,” Farias said.

It turns out he’s not alone. While symptoms are most common in older adults, Farias is among a growing number of adolescents and children being treated for dry eye symptoms at the Dry Eye Center in the UH College of Optometry.

“We believe some of this increase stems from the chronic use of digital devices from the time our children are very young,” said Dr. Amber Gaume Giannoni, director of the Dry Eye Center. “Less than 2 percent of children typically have dry eye complaints, but we’re starting to encounter it much more often.”

It’s not just dry eyes on the rise but also sleepy eyes. New research at the College found that the blue light emitted from digital devices could contribute to the high prevalence of reported sleep dysfunction.

The largest source of blue light is sunlight, but it’s also found in most LED-based devices. Blue light boosts alertness and regulates our internal body clock, or circadian rhythm, that tells our bodies when to sleep.

Study participants wore short wavelength-blocking glasses three hours before bedtime for two weeks, while still performing their nightly digital routine. Results showed about a 58 percent increase in their nighttime melatonin levels, the hormone secreted by the pineal gland especially in response to darkness. Those levels are even higher than increases from over-the-counter melatonin supplements, according to Dr. Lisa Ostrin, the college’s assistant professor who led the study that’s now being talked about all over the world.

“The prevalence of sleep disorders is very high, and we think a lot of the technology is to blame,” said Dr. Ostrin. “This is concerning because sleep is very important for the regeneration of many functions in our body.”

Participants also reported sleeping better, falling asleep faster, and even increased their sleep duration by 24 minutes a night.

Ostrin recommends limiting screen time, applying screen filters, wearing computer glasses that block blue light or using anti- reflective lenses to offset the effects of artificial light at nighttime. Some devices even include night–mode settings that limit blue light exposure.