Dry eye is a common condition without a cure and if you are one of those suffering from the burning, gritty condition that can impair vision and damage the cornea, check if you are blinking your eyes enough.
With computer simulations that map the way tears move across the surface of the eye, researchers discovered that when your eyes are open, the tears get thin right along the edge of the eye.
Using the software programme Overture, researchers recreated the flow of tears on the surface of an open eye, moving from the upper corner and draining through the ducts at the opposite corner.
"One thing we were able to find is that when your eyes are open, the tears get thin right along the edge of the eye, and that is referred to as the 'black line'," said Kara Maki, an assistant professor at Rochester Institute of Technology in the US.
The tears, Maki explained, climb up the eyelid and join a column of fluid that travels along the lids.
Lower pressure sucks the fluid into the meniscus and away from the centre, creating the black line and dry spots in the tear film that can compromise vision and irritate the cornea.
"We confirmed that blinking is necessary to stop this thinning from happening. Every time you blink, the tear film gets repainted on the front of your eye," Maki noted.
It is important to have smooth tear film for optical quality, she explained.
Women are predominantly afflicted with dry eye condition due to hormonal changes associated with menopause.
A cure for dry eye could be in sight with better understanding of the basic dynamics of the tear film.
The study appeared in the journal Physics of Fluids.
