If you're looking for the cause of irritated eyes, the obvious suspect may not always be the culprit.
Last week, Twitter co-founder Christopher Isaac "Biz" Stone had a message for those who stare at their Twitter feed for hours on end: "It's not healthy." Stone says people should visit the popular site, but not dedicate their lives to it.
Beyond the social repercussions of constantly looking at a screen, Stone's statement carried some greater weight -- our eyes could be harmed as well.
Some experts agree, but say the actual screen may not be what's causing the damage. "While computers have no known harmful effects on eyesight, computer users do often complain of eye-related symptoms like eye strain, headaches, fatigue and difficulty focusing," says Surjinder Sahota, president of the British Columbia Doctors Of Optometry. "These symptoms, however, are caused not by the computer screen itself, but rather by the conditions surrounding the computer screen."
Sahota says poor lighting, improper placement of computer equipment and even computer furniture may all cause our eyes to be irritated after staring at a screen too long.
Our eye muscles function like any other muscle in our body. When muscles become fatigued, the eyes may feel uncomfortable or ache and vision may start to blur, Sahota says.
But if your profession requires you to stare at a screen all day, there are techniques to overcome eye irritation -- it's the rule of 20.
"Look away from your computer at least every 20 minutes and gaze at a distant object 20 feet away for 20 seconds," she says.
And size also matters. LCD screens can cause less eye strain than older screens and adjusting your text size for comfort can also help.
Last year, scientists found that our inability to focus on smartphone screens and determine how far away the content should actually be from our eyes, is the reason why they may feel sore after texting.
In the short term, there are ways we can improve our eyesight by making a trip to the grocery store. Here are 10 foods that can help to preserve your vision.
With files from the Canadian Press