Relentless screen use causes dry eye. These days, around half of 18- to 25-year-olds suffer from the condition and 90% have at least one symptom, which can include gritty or burning eyes, blurred vision, sensitivity to light, redness, stringy mucus, itching, pain, or discomfort wearing contacts.

In addition, about half of young adults have lost a large section of a gland in the eye that produces a lipid layer of tear film needed to keep eyes moist.

Those are the findings of a study of 50 students whose average daily screen time hit eight hours.

Untreated dry eye can do more than cause discomfort. It can lead to blurred vision, eye pain, light sensitivity, increased risk of corneal abrasions and ulcers, keratitis, and even vision loss.

What can you do to ease dry eye?

First, try blinking exercises. Close your eyes for two seconds, then open. Repeat. Then squeeze your eyelids together for 2 seconds. Repeat the cycle.

You can also follow the 20-20-20 rule. For every 20 minutes of screen time, take a break and look at an object 20 feet away for 20 seconds. Repeat that throughout the day.

Other things you can do include eating omega-3-rich salmon, maintaining a healthy sleep routine, and managing stress.

If you wear contacts, it's important to make sure they fit well, replace them on schedule, clean them well, and do not wear them when sleeping, showering, or swimming.