Staring at iPads and smartphones make eyes itchy, inflamed and gritty, says expert.
The mind can 'forget' to blink, when we are concentrating on the screen, says Christine Purslow, director of the contact lenses and anterior eye research unit at Cardiff University. It affects the eye's lubrication system.
We normally blink 12-15 times a minute, but using a computer screen can cut this to seven or eight a minute, adds Purslow. This leaves the tear film - the lubricating substance that protects eye surface, not working properly.
About 30 percent of those over 50 years have dry eye but numbers are rising, with many more young people affected, the Daily Mail reports
"As a nation we are getting older, which means the proportion suffering age-related dry eye is increasing, where the tear film over the surface of the eye deteriorates with age," Purslow said.
"But younger people are experiencing problems because of the modern office, with computers and air conditioning making it worse, as well as home use of display screens," said Purslow.
"Using a screen on your lap, the iPad for example, has a similar effect to using a screen on your desk - you blink less," said Purslow. Soft contact lens wearers were particularly at risk. Clinical trials show that tear substitutes can remedy the problem by stabilising the tear film within two to three months.