Eye strain is one of the most common eye related complaints that people have. It may occur due to a number of reasons and is very easy to cure in most cases. Medically, it is called asthenopia. With the increasing use of computers in homes and workplaces, instances of eye strain have risen sharply.

Also called astheopia, it is a symptom rather than an eye disease. It usually occurs when eyes get tired and fatigued due to intensive use. It manifests itself as discomfort in looking at things. Most people have experienced eye strain in some form or the other. It is not a serious condition and can be treated through rest alone. However, if eye strain occurs frequently, it may be taken as a sign of other more serious eye diseases.

Symptoms

The common symptoms of eye strain are easy to identify. They include discomfort in the eyes, dryness or conversely, mild tears, soreness, and an inability to concentrate on things. Other symptoms include pain at the back of the neck and temples, headaches, and blurred double vision.

There are no medical tests to determine the severity or degree of the strain; it is subjective, varying from patient to patient. It is also lifestyle dependent - those used to spending long hours working before computer screens or reading will suffer less than others. 
If eye strain does occur frequently, then it is advised that you consult your ophthalmologist as it can be a symptom of an underlying eye disease.

Causes

Eye strain is typically caused by intensive use of the eyes for a long period of time. Visually intensive tasks such as reading (especially if the print is small), watching television, working with computers, playing video games or driving are common causes of eye strain. Working in dim light can also cause tightening of the muscles in the face around the eyes, leading to eye strain.

In some cases, the strain may be a symptom of underlying ocular conditions such as presbyopia, nearsightedness or farsightedness. Strain in those already suffering from these conditions can be an indicator of the need for higher power corrective optical instruments (glasses or lenses).

Treatments

Treating most forms is as simple as taking a rest for a few hours. Relaxing the eyes naturally relieves them of any built up stress and fatigue. Certain exercises such as closing the eyes for a few minutes, massaging the temples, etc. can also provide temporary relief. If you are going to spend long hours before a computer or on other visually intensive tasks, it is recommended that you take periodic breaks.

You can also reduce the intensity or frequency of eye strain by working in more suitable conditions. If using computers, try using a LCD or TFT monitor instead of a CRT one. Make sure that you work in well-lit conditions and always maintain a healthy distance between yourself and a computer or television screen. Take a break every hour and stretch your arms, back and shoulders to relieve your body of built up stress.

If strain leads to excessive dryness of the eyes, you can get an over-the-counter eye drop for relief. In almost all cases, eye strain is not serious and can be easily cured through rest, but if it persists for a long time, it may be wise to consult an ophthalmologist.