COMPUTER VISION SYNDROME AN EMERGING PANDEMIC OF 21st CENTURY

COMPUTER VISION SYNDROME
AN EMERGING PANDEMIC OF 21st CENTURY

Computer vision syndrome (CVS) is defined as a of eye and vision problems that are experienced during computer use and is a repetitive strain disorder.

SYMPTOMS OF CVS-
(1) Eyestrain (2) Blurred vision (3) Dizziness or nausea (4) Headaches (5) Red, dry or burning eyes (6) Increase in nearsightedness (7) Change in colour perception (8) Slow refocusing (9) Excessive fatigue (10) Neck, shoulder and back pain (11) Eye- tearing problems and/or occasional double vision.
The use of computers leads to the following four types of problems.

(A) EYESTRAIN-
Characters displayed on the computer are made up of small dots or pixels. Focussing on these pixel characters is difficult The eyes focus on the plane of the computer screen but cannot sustain the focus. They focus on the screen and relax to a point behind the screen, called the resting point of accomodation (RPA) This constant flexing of muscles causes fatigue and generates burning and tired eyes. 

(B) ACCOMODATIVE SPASM-
Pseudo-myopia is a condition when the eyes are locked in a focus at near and won't relax easily. This occurs due to the constant effort needed to focus near objects and to sustain that focus can lead to accomodative spasms. If the cause of overfocussing is not corrected, the pseudo myopia becomes structuralized and the patient becomes truly myopic.

(C) DRY EYE-  
Studies show that people blink about three times less than normal while working on the computer. Tears coating the eyes evaporate more rapidly during the non blinking phase and cause dry eyes.

(D) BODY FATIGUE- 
Constant working on the computer can cause neck and shoulder stiffness as well as stress headaches which can cause referred pain in the jaw.

STEPS TO PREVENT CVS
Computers do not harm the eyes. Practically all computer problems are preventable and correctable. Having an accurate, and ergonomically appropriate workstation can make a huge difference in managing visual comfort while using the computer. Following steps help in reducing eyestrain while using the computers. 

a. REGULAR EYE CHECKUPS AND USE OF COMPUTER GLASSES.

b. USE PROPER LIGHTING AND MINIMIZE GLARE.
Brighter is not always better- Excessive overhead lighting frequently causes glare. This can be avoided by using the following steps.
1- Use of indirect lighting.
2- The light source should be from behind, coming across the shoulder and hitting the screen at right angles.
3- Keep the computers away from the windows.
4- Do not work in the dark.
5- Install an anti-glare screen on the monitor and use anti-reflective coated glasses to reduce uncomfortable reflection.
 
c. POSITION OF THE COMPUTER MONITOR-
1 - The optimal screen position is about 10 to 20 degree angle below eye level. This prevents dry eye and head and neck aches. 
2- The distance of the screen from the eyes should be 20-26 inches. 3-Dust the screen with an anti-static cloth regularly. 
4- Keep the texts and other material close to the screen, perhaps on a mount adjacent to the monitor. 

d. MONITOR DISPLAY QUALITY-
1 - Resolution- refers to a monitor's pixel density. Generally the higher the resolution the better.
2- Dot pitch- affects the sharpness of the display. The lower the number, the sharper the image
3- Refresh rate- It refers to how often the monitor redraws the contents on the screen. The refresh rate should be 70 Hz or higher.

e. EXERCISE WHILE WORKING-
1. Look away from the computer screen every 30 minutes and focus for 5-10 seconds on a distant object.
2. A break of 10 minutes is advised every hour.
3. For readjusting the focusing it is recommended to look far away for 10-15 seconds and then near for 10-15 seconds. 4. Stand up, move about and do stretching exercises frequently.

f. DRY EYE PREVENTION-
1- Blink more often.,
2- Reduce air currents over the workstation.,
3- instill artificial tear drops regularly as advised by you doctor.
Issued in public interest by health education cell , Ahuja Eye Centre,Aligarh