Definition:
Computer vision syndrome (CVS) is a temporary condition resulting from focusing the eyes on a computer display for protracted, uninterrupted periods of time.

Symptoms:
Some symptoms of CVS include headaches, blurred vision, neck pain, fatigue, eye strain, dry, irritated eyes, and difficulty refocusing the eyes. These symptoms can be further aggravated by improper lighting conditions (ie. bright overhead lighting or glare) or air moving past the eyes (e.g. overhead vents, direct air from a fan). CVS has not been proven to cause any permanent damage to the eye.

Pathophysiology:
CVS is caused by decreased blinking reflex while working long hours focusing on computer screens. The normal blink rate in human eyes is 16-20 per minute. Studies have shown the blink rate to decrease to as low as 6-8 blinks/minute for persons working on the computer screen. This leads to dry eyes. Additionally, the near focusing effort required for such long hours puts strain on ciliary muscles of the eye. This induces symptoms of asthenopia and leads to a feeling of tiredness in the eyes after long hours of work. Some patients present with inability to properly focus on near objects after a short duration. This can be seen in people aged around 30-40 yrs of age, leading to a decrease in the accommodative focusing mechanisms of the eye. This can be a setting for early presbyopia.


Treatment:
Dry eye is a major symptom targeted in the therapy CVS. The use of over-the-counter artificial tear solutions can reduce the effects of dry eye in CVS.
Proper rest to the eye & its muscles is recommended to relieve the associated eye strain.
A routinely recommended approach is to consciously blink the eyes every now and then (this helps replenish the tear film), and look out of the window into a distance object or the sky - (this provides rest to the ciliary muscles). One of the catch phrases is the "20-20-20 rule": every 20 minutes, focus the eyes on an object 20 feet (6 meters) away for 20 seconds. This basically gives a convenient distance & time-frame for a person to follow the advice from the ophthalmologist. Otherwise, the patient is advised to close his/her eyes (which has a similar effect) for 20 seconds, at least every half hour or even more frequently.

Source: Wikipedia

---

Dr.Mahdi