More screen time, more strain
The tasks we use our eyes for have certainly changed. Rather than scanning the forest for the fixings for our next meal, we peruse restaurant reviews on a smartphone to determine where to eat.
But does staring at computer screens and even smaller devices jeopardize our eye health, potentially putting our corneas — the transparent membrane at the front of the eye responsible for transmitting and focusing light — at risk as some recent studies suggest?
Important to take breaks
"I have never seen this in my practice, nor am I aware of any conclusive studies that link corneal damage to extended computer use," says Dr. Mary E. Davidian, the founder and medical director of Highland Ophthalmology Associates, LLC, which specializes in eye diseases and cataract, cornea and refractive surgery. "And there is no evidence that computers emit any radiation or damaging ultraviolet light."
That said, however, the use of electronic devices presents tasks that are imposing for the eyes, she says, and can result in eye strain with symptoms of headaches, fatigue, neck and muscle aches — and difficulty focusing.
"The tiny muscle in the eye that controls the shape of lens, which gives the eye its ability to focus, can spasm," Davidian says, stressing the importance of taking frequent breaks and looking at points in the distance. And people who are in their 40s and older are already experiencing some degree of presbyopia — an age-related change in the elasticity of that tiny muscle that affects focusing and makes reading the fine print more difficult.
Less blinking, drier eyes
Additionally, people blink less frequently when working on a computer.
"A blink is like a windshield wiper that spreads the tear film and lubricates the eye," says Davidian. "We typically blink 12 times a minute. But the blink rate drops to about five times a minute when at a computer."
This decline in lubrication can manifest in increased corneal dry patches.
"But this is not a permanent change, nor does it cause permanent damage," she says.
However, extremely severe dryness that causes stinging, burning and a sandy-type sensation, such as with the autoimmune disease Sjogren's syndrome, can, left untreated and over time, lead to a breakdown of the cornea and infection.
See a professional
Davidian says chronic dry eyes should always be discussed with an eye-care professional. Over-the-counter lubricating drops are fine to use, but some brands are better than others. And there can be a number of causes of a burning sensation, including allergies, affecting treatment options.
"We are one of the few offices to offer a tear osmolarity test that objectively measures the concentration of tears and gives a baseline for treatment," she says.
Easy on the eyes
Dr. Mary E. Davidian offers the following tips to mitigate eye strain while at your computer:
• Follow the 20-20-20 rule. After 20 minutes at the computer, take a 20-second break and focus at a distance of about 20 feet to prevent a spasm of the tiny muscle in the eye that controls the lens.
• Location matters. Position the computer 18-28 inches from your torso.
• The eyes have it. Position the screen 4-9 inches below your eyes, rather than at or above eye level.
• Do adjust your screen. Adjust for a screen brightness that is comfortable and a contrast that makes letters clear.
• Avoid glare. Create good lighting that eliminates glare. Lighting from behind is preferable.