More squinting means less blinking

COLUMBUS, Ohio — The more people squint while staring at a computer screen, the less likely they are to blink, leading to a potential increase in dry eye, new research shows.

James Sheedy, OD, PhD, and colleagues at Ohio State University found that “just a slight amount of squinting reduced blink rates by half, from 15 blinks a minute to 7.5 blinks a minute,” according to a press release from Ohio State.

“People tend to squint when they read a book or a computer display, and that squinting makes the blink rate go way down,” Dr. Sheedy said in the release. “So if your job requires a lot of reading or other visually intense work, you may be blinking far less than normal, which may cause eye strain and dry eye.”

The researchers asked 10 college students to squint at various levels. All participants had 20/20 vision. Participants were first asked to completely relax their eyes; four subsequent times they were asked to squint in increments ranging from 5% to 50%. The subjects were asked to continuously look at a black dot in the center of a computer display.

Blink rates decreased from an average of 15 blinks per minute when the eyes were relaxed to 7.5 blinks a minute when the subjects squinted 5%; the blinks per minute were further reduced to 4.5 when the subjects squinted at the 50% rate.

The study is published in Optometry and Vision Science.