(Mark Prigg @ mailOnline)Researchers have come up with a simple exercise they claim could stop computer users getting eye strain.

They say blinking 20 times in a row every 20 minutes should be combined with looking away from the screen for 20 seconds and focusing on an object 20 feet away.

The '20-20-20-20' strategy has been designed as a solution to computer vision syndrome (CVS) which affects millions of workers and games addicts.

Scientists claim blinking 20 times in a row every 20 minutes should be combined with looking away from the screen for 20 seconds and focusing on an object 20 feet away

Symptoms such as dry and tired eyes, headaches and sore necks and joints are usually temporary but for many can be a daily problem that leads them to seek medical help.

Those most at risk are anyone who spends three or more hours a day in front of a computer, but it can be painful and lead to many being prescribed glasses.

But although it may look a bit odd, a regular bout of blinking could help, said researcher Dr Edward Mendelson from the Southwestern Medical Centre at the University of Texas. 

He said: 'Every 20 minutes the computer user should take a break for 20 seconds and look at objects that are 20 feet away.

'And give yourself 20 good blinks - blinking is nature's way of keeping the eyes moist and those blinks help to lubricate and refresh.'

Anyone who spends long periods in front of a screen is at risk but it is often worse for workers because of the sterile and unnatural conditions in modern office blocks.

Experts say the advice could help those who suffer from eye strain after a day staring at a computer screen

Dr Mendelson added: 'Today's offices are commonly cool and dry, which is nice and comfortable, except for the eyes.'

Eye drops taken before work begins can help with dry eyes but a break from a screen can also help with the other elements of CVS like neck, muscle and headaches from being sat in one position for too long, researchers say.