Staring at the computer all day... okay for my eyes?
My eyes feel dry and swollen after hours of staring at the computer monitor. Is there any long range harm caused by spending both work and play time in front of the computer? I work out, and eat a healthy, low-fat diet. I don't have any other vices except perhaps a higher than normal caffeine intake.
— Computer nerd
Dear Computer nerd,
Whether you’re a computer nerd, geek, or brain, you will likely not have to worry about long-term damage to your eyes from the many hours spent at the computer (or other devices including smartphones, e-readers, and tablets). You may experience some minor health concerns, such as dry eyes, but fear not — there are preventive measures that a person can take to help alleviate discomfort from long hours in front of a screen.
So what causes this feeling of dry, strained eyes? Computer vision syndrome (CVS), or digital eye strain, is a condition that results from prolonged use of electronics with a digital screen and includes five major symptoms: eye strain, headaches, blurred vision, dry eyes, and neck or back pain. One reason these symptoms occur is because folks who are using a digital screen for an extended period of time don’t blink as often, which is the body’s way of lubricating the eye. In fact, those using a digital screen blink only about 4.5 times per minute, while those not behind a screen blink around 18 times per minute. Reading on a screen is also more taxing to the eyes, as letters on a screen aren’t as sharply defined compared to print and the contrast between those letters and the background is not as sharp either. Additionally, a person’s peepers may encounter glare from lights in your home or windows, which makes items on a screen much harder to see. In turn, this makes the eyes work a bit harder than they would if a person was simply reading from a printed page.
The viewing distance and angles used by those who read off a digital screen can also contribute to the experience of symptoms, as this can place additional demands on one’s eyes. Lastly, the computer user’s current visual ability and the length of time spent viewing digital screens factors into the degree to which they experience these undesirable symptoms. For most folks though, these symptoms will go away after screen time is over. The American Optometric Association does note, however, that some people may continue to experience symptoms even after they stop using the computer. If the cause isn't addressed, the symptoms may recur and worsen with continued digital screen exposure.
Prevention can be a key component in addressing any discomfort. The first line of defense is to get your eyes examined by a professional, either an optometrist or an ophthalmologist. It’s noted that folks who have uncorrected vision impairments, such as farsightedness or astigmatism, may be more susceptible to these symptoms. Letting the optometrist or ophthalmologist know about your average daily screen time may help them determine if any specially designed contact lenses or eyeglass lenses may be beneficial (particularly if you already use either one to correct your vision).
One commonly touted prevention method is to wear blue light glasses, which claim to reduce strain on the eyes due to blue light. However, there is no evidence that these glasses result in improvements in eye strain, as most of the discomfort from staring at computer screens doesn’t come from blue light. Due to this, making changes to the screen display and how you use a computer can help alleviate or prevent some of the eye irritation and fatigue associated with CVS. These adjustments may include:
- Using the 20/20/20 rule: After 20 minutes of computer use, look at an object offscreen 20 feet away for at least 20 seconds.
- Making sure the computer monitor is at least 20 to 28 inches away from the eyes.
- Placing the screen at a viewing angle of 15 to 20 degrees, or 4 to 5 inches, below horizontal eye level.
- Making a conscious effort to blink more when viewing a screen.
- When using a reference document, making sure it’s placed above the keyboard and below the top of the screen so that you don’t need to reposition your head from document to screen. A document holder may also help accomplish this.
- Adjusting lighting in the workspace or room to reduce glare or get a glare filter for the screen.
- For those working in offices with windows, making sure the window is located to the left or right of the worker (not behind or in front of the monitor). Try to use drapes or blinds to further reduce glare.
Adapted from the American Optometric Association.
It's great that you've already adopted some habits that keep your body moving. Incorporating some of these other tips may help get your eyes on the same path. Getting your vision checked out (and corrected, if needed) and taking a breather… er, blinker every now and then can keep you typing, surfing, reading, designing, studying, watching, playing, and more.
Originally published May 18, 1995
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