COMPUTER VISION SYNDROME
Looking at a computer monitor for any period of time that requires any cognitive or thinking can cause various forms of eyestrain. Monitors project information forward to the front of the screen in a fashion the makes the centers of each letter a little darker than the outer portion of that letter. The outer edges of the letters are not perfectly straight. These to situations are beyond our control. In a percentage of the population, the difficulty with different center to edge intensities and the non uniform letter edges causes the focusing system to rock back and forth in an attempt to lock on the letters of he words on the monitor. As the day progresses, the constant rocking causes may visual symptom, including headaches, blurry vision, intermittent double vision, loss of concentration, loss of productivity, and secondary irritability to name a few. This problem can best be addressed with a comprehensive eye evaluation and computer eye evaluation. We have been seeing patients nationwide since 1995 for these types of problems. See and take our Ocular Repetitive Stress Syndrome questionnaire.
Computer Eyestrain means different things to different people. It can be experienced as burning, tightness, sharp pains, dull pains, watering, blurring, double vision, headaches, and other sensations, depending on the person. It can result in loss of place while reading visual memory loss, agitation at work, and decreased productivity as the goes on. If you have any eye discomfort caused by viewing a monitor, keyboard, paper work while using the computer, or from visually rocking back and forth, you may call it computer eyestrain.
In VDT workstations, the principal external factors affecting the ability to see well are: glare, the luminance (brightness) difference between what is being looked at and its immediate environment: the amount of light the distance between the eye and the screen and document the readability of the screen and document the worker's vision and his or her corrective lenses
Watch out for direct glare. Direct glare involves a light source shining directly into the eyes ---ceiling
lights, task lights, or bright windows. To determine the degree of direct glare, you can temporarily shield your eyes with a hand and notice whether you feel immediate relief.
Reflected glare, such as on computer screens, sometimes cause eyestrain. But its worst effect may be causing you to change your posture to an uncomfortable one, in order to see well.
One of the most overlooked causes of eyestrain in offices is contrast ---usually, a dark screen surrounded by a bright background such as a window or a lit wall. The best solution is to find a way to darken the
area around the screen. This problem occurs mainly on screens with light letters on a black background. Some ocular and retinal problems can also be a causative agent. For this possibility, a comprehensive eye evaluation would be highly recommended. Contrast sensitivity testing is also available in our office for near and far viewing.
How much light is right? It depends on your age, the quality of the print you're reading, and other factors. There should be plenty of light for easy reading, but too much can, depending on the person and its projection on to the material being viewed can cause eyestrain.
Eyes are strained more by sustained close viewing than by distant viewing. The "right" distance for computer monitors and documents depends entirely on how clearly they can be read at a given distance. If you are having a difficult time determining the correct distance, a call to our office or e-mail might help.
If you gaze at something too long, your eyes can tire. Eyes need to focus at different distances from time to time and require different blink rates and patterns. Eye muscles fatigue and eyes dry out. It's a good idea to follow the "20/20 rule"---every twenty minutes, look twenty feet away for twenty seconds.
Can computer work cause nearsightedness? Some studies have shown a correlation including one I did in 1995-6. We found a little over a quarter of a diopter change in computer programmers in a one month period. More research is needed to make a definitive statement one way or the other. It's likely that computer work makes you realize that you need glasses, distance and or for the computer.
Sometimes eyestrain is just a case of dry eyes. Lowering the monitor can help. Looking downward means more of the eye surface is covered by the eyelid, and two other things happen: the eyes unconsciously blink more, can recoat the eyes more frequently. The best advice is to consciously blink more. If this does not achieve the desired results, than a call or e-mail to our office is essential. Sometimes a tear lubricant is all you need. Lid hygiene can be another cause that requires seeing a doctor. For these reasons, an office visit makes sense if dry eyes persist.
People who need bifocals may have to consider other options besides bifocals. Two good ones are: "Computer glasses" that focus at the right distance for the computer screen: or a special bifocal that corrects for the monitor and paper or desktop work.
Bifocal wearers often experience sore necks and shoulders because they have to tip their heads back to see the computer screen. Lower the screen as much as possible --if it sits on the CPU, move the CPU. If necessary, remove the monitor's tilt-swivel base (consult a computer hardware person
first) to gain a couple additional inches. Lower the work surface that the monitor sits on.
Here is no substitute for a thorough visual assessment and computer vision analysis to help in determining your visual needs. Call or e-mail us for more information on Computer Vision Syndrome and Ocular Repetitive Stress Syndrome.