Posts Tagged ‘computer’

Additional Thoughts on Computer Vision Syndrome

Tuesday, April 6th, 2010

There’s the old joke:   A man goes to the doctor and says ‘doc, my arm hurts when I move it like this,’ and the doctor says ‘then don’t move your arm like that.’    If only finding a solution to Computer Vision Syndrome were that easy.   But the computer plays such an integral role in all of  our lives that avoiding it would spell trouble for our careers or our ways of communication.   Since my first post on Computer Vision Syndrome (CVS) was the most popular blog post so far this year, I wanted to add some follow-up ideas.

The most effective solution to CVS is specialized prescription computer glasses.   As mentioned in the first post, computer glasses allow for the correct amount of magnification at computer distance and thus relieve near-focus (accommodation) stress which often causes headache.   These glasses also are treated with anti-glare technology which further comforts the eyes by relieving glare strain produced by the computer screen.

But there are also some ergonomic approaches to CVS, such as:

1.  Take a look at the monitor:    Use an LCD screen with the highest resolution possible.   Most of us are using LCD screens, but some may still be using the older CRT monitors that are not flat-screens.  These older monitors have markedly reduced resolution and this lower resolution tricks the accommodation system into over-working to improve clarity.     Even with a LCD flat screen, it’s important to consider the brightness of the display.   Backgrounds that are too bright inherently create glare and eyestrain over long periods of time.    Consider adjusting the brightness of your monitor to match the brightness of its surroundings.

2.  Don’t forget lighting:  more is not always better.   That holds true with respect to overhead or room lighting when working at the computer for long periods of time.   To reduce strain at the computer, it’s best to avoid very bright lighting.   The eyes will be more comfortable if the environmental lighting is somewhat subdued.   Try to keep the major lighting source to your side, rather than directly in front or back of you while at the computer.

3.  Working distance: the optimal distance to be seated from the computer screen is about 20-24 inches away.   It is also optimal to have the computer screen 10-15 degrees below their eyes.

4.  Take a break, actually take lots of them: I advocate the 20-20-20 rule.  It’s simple and it can help reduced fatigue at the computer.   Every 20 minutes, look at something 20 feet away for at least 20 seconds.   These frequent breaks allow the accommodation (near-focus) muscles to relax and reset.

As always, if you have any questions or comments, please post them here or email us.   Happy computer work!

Computer Vision Syndrome

Monday, March 15th, 2010

It is estimated that nearly 140 million Americans use a computer at work, home, or school on a daily basis.   While computers have dramatically improved our lives over the last 20 years, they haven’t been quite so kind to the eyes viewing them.    Millions of people, using the computer more than 2 hours a day, have experienced Computer Vision Syndrome (CVS).

What is Computer Vision Syndrome?

CVS is a combination of visual and physical symptoms due to the stress placed on the eyes with extended and chronic computer use.     It is most often accompanied by:

  • Headache
  • Loss of focus
  • Burning/tired eyes
  • Blurred vision
  • Shoulder/back aches

What Causes CVS?

In my experience with many CVS patients, there appears to be 3 main contributing factors:

  1. Constant contraction of the near-focus muscles of the eye: this produces fatigue, headaches, fluctuating or decreased focus.
  2. Glare from the computer screen:  interferes with clear vision, producing eye strain and uncomfortable vision.
  3. Decreased blinking of the eyes:   results in greater evaporation of moisture from the eyes which then causes dryness, burning, redness and further blurry vision

Solutions for CVS

The best approach to CVS is a two-pronged treatment plan.   The first step is prescription Computer Glasses, based on careful testing of your visual tendencies when focusing up close.   This will relieve the focusing demand & stress created by chronic computer use.   Computer glasses will also incorporate Anti-Glare Treatment, which will free your eyes from computer glare and will allow for clear AND comfortable vision.   The second aspect of treating CVS is to address the physical symptoms created by reduced blinking.   Careful assessment of your ocular surface will allow for recommendations of artificial tears specific to your situation.   In some cases, complete relief may require prescription eye drops or the installation of tear duct plugs to retain your own natural tears.

If you find yourself in front of the computer on a daily basis, make sure to discuss any of these issues with your optometrist or schedule an appointment to see us.    Your eyes don’t have to suffer from CVS !

Study Finds 66% Increase in Myopia in Americans aged 12-54 Years

Thursday, January 21st, 2010

A recent study in the Journal of Ophthalmology compared the incidence of myopia (near-sightedness) from the early 1970’s to 2004.   The researchers found a 66% increase in myopia over that 30 year time frame.  A 66% increase!   I get a little bored with statistics sometimes, but that is an amazing increase over such a short period of time.   The study goes on to say that in the early 1970’s, about 25% of Americans had myopia and that in 2004 that number was near 46%.

Unfortunately, the study was strictly observational and didn’t investigate the causes of this drastic increase.  There are many studies that conclude that myopia does have a genetic component.   Myopic parents are more likely to have myopic children.  But it’s impossible to predict the presence or degree of myopia in children based on the parent’s prescriptions.

We also know, through a number of studies, that environmental conditions play a role in the development of myopia.  “Law school myopia” is a term that is used often.   It relates to a famous study that showed law school students had a significant increase in myopia at graduation compared to their first day of graduate school.  This increase, which isn’t exclusive to law school students, was attributed to the rigorous visual demands that extensive reading can place on a person’s visual system.   When a person is reading, accommodation muscles are contracted to allow the eye to focus at close distances.  

Having those muscles contracted for long periods of time will restrict their ability to relax and can translate into in an increase in near sightedness.   Imagine you contract your bicep at full strength for two hours and then try to relax it….you most likely will not be able to move your arm back into its normal position.   For some individuals, this may happen with their accommodation or near-focusing muscles.

Does the dramatic increase in computer use in modern times account for some of this myopia increase?    More detailed studies on the causative factors will be needed.  But, using the computer does require the same accommodation muscles that are seen in “law school myopia.”   Obviously, we can’t stop using the computer or reading or studying.  But there are some other things that can help.

Taking breaks from up-close visual tasks is key.  Every 15-20 minutes look up from the reading material or computer and look at something far away—maybe a clock or a poster or painting.   Allowing your eyes, for at least 30 seconds, to focus on that target at a distance will relax those accommodation  muscles.

Still, the study is surprising.  And hopefully it will trigger more studies on the causes for such a dramatic increase in myopia in the U.S.