Computer Vision Syndrome

What is Computer Vision Syndrome? (CVS) “A complex of eye or vision problems which are experienced during and related to computer use.”

Superior and lateral rectus muscles, optic nerve.

Superior and inferior oblique muscles, superior,inferior, and lateral rectus muscles, with eye.

Superior and inferior oblique muscles, medial and inferior rectus muscles.

Eye with rectus muscle attachments.

Why are we concerned about CVS?  143M American workers work on a computer and estimates are: - 88% suffer from computer eyestrain  90% of the 143M U.S. workers use computers today for more than 3 hours per day. This problem effects productivity by 4 to 19%.

What are the symptoms of CVS?  Eyestrain  Eyestrain (sore or fatigued eyes)  Headache  Slowness in changing focusing distance  Eye irritation (burning, dryness, redness)  Neck, back & shoulder pain

The Problem u It has multiple causes & symptoms. u Prolonged viewing is the most common cause and it has been proven to be unnatural for the human optical system. u Humans blink approximately 22 times per minute. During computer use humans blink only 4 to 6 times per minute.

Other Problems u Lower blinking rates cause eye moisture to evaporate (dry eye). u Dry eye causes people to arch their foreheads in a effort see better, thus causing headaches. u Many people assume awkward, unnatural postures, thus causing sore backs, stiff necks & hurting shoulders.

FAQ’s What Causes Computer Vision Syndrome?  CVS is caused by our eyes and brain reacting differently to characters on the screen than they do to printed characters. Our eyes have little problem focusing on most printed material, which is characterized by dense black characters with well-defined edges. Healthy eyes can easily maintain focus on the printed page. Characters on a computer screen, however, don't have this contrast or well-defined edges. These characters (pixels) are brightest at the center and diminish in intensity toward their edges. This makes it very difficult for our eyes to maintain focus and remain fixed onto these images.

Will Glare Screens Prevent CVS?  Glare screen filters may help somewhat, but they will not solve your computer vision problems because they only affect glare from the computer screen — not the visual problems related to the constant refocusing of your eyes when working at a computer.  Only when your eyes can focus clearly at the plane of proper distance on the computer screen can they experience relief from the fatiguing effects of CVS. An anti-reflective coating (AR) is also highly recommended on all computer eyeglasses. An AR coating prevents glare and reflections on the front and the back of the lenses that would interfere with focusing on the screen. FAQ’s

Will Computer Eyeglasses Make the Screen Clearer?  Yes, because they will eliminate the constant refocusing effort that your eyes go through when viewing the screen. It has also been proven clinically that having the correct prescription in computer eyeglasses increases productivity and accuracy. FAQ’s

What About the Tints I've Heard of for Computer Lenses?  If you work in a brightly lit office, you may benefit from a light tint applied to your computer lenses. This can cut the amount of light that reaches your eyes and provide relief in some cases. But tints and filters don't address the underlying cause of computer eyestrain. FAQ’s

Does Every Computer User Need Computer Glasses?  More than 70% of computer users need computer eyeglasses.** In fact, according to a study out of the University of California, Berkeley, 25%-30% of children would benefit from computer eyewear. FAQ’s

Will My Reading Glasses Work at the Computer?  Not necessarily. In most cases your reading glasses are probably not going to do the job. The correct computer eyeglasses will optimize your comfort and productivity at the computer screen while also allowing you to read and see out at some determined distance (10-13 feet). Reading glasses are usually prescribed to read at a distance of 16"-18", but computer glasses are usually designed to work at 18" to 28". FAQ’s

Can CVS Cause Other Body Pains? Headaches, sore neck, shoulders or back are common complaints and there are two main causes, one having to do with your vision and one not. – Vision So where do the other aches and pains come in? These are often caused by trying to read the screen through the bottom portion of bifocals, or though half-eye reading glasses. You tip your head up or lean forward to see and this unnatural posture makes you sore. FAQ’s

Isn't Ergonomics the Solution to Computer Eyestrain?  Ergonomics is important — changing one's computer workstation can certainly help to minimize other physical symptoms. But ergonomics cannot fix a visual problem. The proper prescription computer eyeglasses at the proper computer distance (18" to 28") is most important. This can be done only with the right computer lens prescription. FAQ’s

10 Steps to Reducing Computer Eyestrain 1.Get a computer eye exam. 2.Use proper lighting.  Eyestrain is often caused by excessively bright light coming in from outside and excessively bright light inside. When you use a computer, your ambient lighting should be about half that used in most offices. Eliminate exterior light by closing drapes, shades, or blinds. Reduce interior lighting by using fewer light bulbs or fluorescent tubes, or use lower intensity bulbs and tubes. If possible, position your monitor so that windows are to the side of it, instead of in front or back.

3.Minimize glare.  You may want to install an anti-glare screen on your monitor and, if possible, paint bright white walls a darker color with a matte finish. Again, cover the windows; when outside light cannot be reduced, use a computer hood. Have an anti- reflective coating applied to your glasses. This will prevent glare and reflections on the back side of your lenses 4.Adjust the brightness of your computer screen.  Closely match the brightness of the environment with that of your computer screen. Make sure that the text size and color are optimized for the most comfort. 10 Steps to Reducing Computer Eyestrain

5.Monitor Display Quality Refresh rate: how often your monitor redraws the content on the screen. A too-low rate can be hard on your eyes, and a very slow rate causes a noticeable and irritating flicker. Resolution: a monitor's pixel density: the more pixels, the higher the level of detail. Generally, the higher the resolution the better. Dot pitch: affects the sharpness of the display. The lower the number, the sharper the image. Most monitors have a dot pitch between 0.25 mm (millimeters) and 0.28 mm; 0.28 or lower is desirable. 10 Steps to Reducing Computer Eyestrain

6.Blink more often.  Blinking is very important when working at a computer — it rewets your eyes to avoid dryness and irritation. When working at a computer, people blink less frequently — about five times less than normally, according to studies. Tears coating the eye evaporate more rapidly during long non-blinking phases and cause dry eyes. Office buildings may have excessively dry environments that also reduce tearing.dry eyes  Also try this exercise: Every 30 minutes blink 10 times by closing your eyes as if falling asleep (very slowly). This will help rewet your eyes 7.Exercise and stretch your eyes.  An hourly exercise to readjust your focusing is to look far away at an object for seconds and then near for seconds, rocking your focusing back and forth between near and far. Do this 10 times. Both of these exercises will help you prevent strained near vision and stretch your focusing muscles 10 Steps to Reducing Computer Eyestrain

8.Take frequent breaks.  20/20/20 – every 20 minutes look at something at least 20 feet away for 20 seconds.  Every 50 minutes on a computer, change tasks for 10 minutes. 9.Modify your workstation.  If you need to look back and forth between a printed page and your computer screen, this can cause eyestrain. Place written pages on a copy stand adjacent to the monitor. Properly light the copy stand; you may want to use a desk lamp, but make sure it doesn't shine into your eyes or onto the computer screen. Adjust your workstation and chair to the correct height. Purchase ergonomic furniture to insure proper screen locations and posture. 10 Steps to Reducing Computer Eyestrain

10.Exercise even when sitting.  Anyone in a sedentary job, especially those using computers, should stand up, move about, or exercise their arms, legs, back, neck, and shoulders frequently. NIOSH recommends several sitting, stretching, and joint rotating exercises for computer users 10 Steps to Reducing Computer Eyestrain

The Solution Keep computer screens slightly below eye level inch from the screen Keep contrast & brightness at moderate levels Keep screen clean Reduce screen glare Frequent short breaks Purposely blink rapidly

Our eyes involuntarily move to the RPA, and then strain to regain focus on the screen. This continuous flexing of the eyes' focusing muscles creates fatigue and the burning, tired-eyes feeling that is so common after long hours at the computer.