the importance of blinking
why, exactly? one main factor is that screen time disrupts the body’s protective eye blinking.
“we could be blinking as little as six times less than what we should be blinking normally. so that makes for tear film instability and also for evaporation of the tear film that’s supposed to cover the surface of the eye,” khouri explains. people normally blink about 15 to 20 times a minute or about 11,500 times a day. with dry eyes, the nerves of the cornea are exposed to the motion of the eyelid during blinking, so each blink can be irritating and even painful.
when you blink, you’re spreading fresh tears across your eye surface to keep it lubricated and clear of any debris, so you prevent irritation and infection, and what you’re looking at is clearer and sharper as well. since there are no blood vessels on the surface of the eyes, tears also bring oxygen and nutrients to those surface cells to support eye function.
scientists from japan have looked at blinking as a momentary state of wakeful rest to give you a mental break and improve focus afterward.
the role of tears in eye health
tears are primarily made of water, but they also contain oil that helps to keep the water in contact with the surface of the eye longer, khouri says. if you’re not producing enough oil because glands are clogged or there’s inflammation in your eyes, that can also bring on dry eyes, fatigue and irritation. oil production also naturally decreases with age, so just like your skin typically becomes dryer as you age, your eyes can become dry as well. adding in a lot of screen time can exacerbate the symptoms. about 90 per cent of her patients with dry eyes are women over 50.
the risk is also higher for people with inflammatory disorders, like rheumatoid arthritis, thyroid disease, diabetes, even rosacea. “patients that have inflammatory disease, if we take a sample of their tears, we will see inflammatory markers in their tears, so inflammation and dry eye are connected,” khouri notes.