The widespread use of computers in our daily lives have also given rise to some new medical conditions. Computer vision syndrome (abbreviated as CVS) is one such modern occupational health hazard that afflicts both children and adults. It is believed that 90% of the population that uses computers for more than three hours a day is suffering from computer vision syndrome (also known as computer sickness). Although no long term complications of computer vision syndrome are known, this condition is associated with significant pain and discomfort that disrupts daily work and life activities.
Computer vision syndrome is not a disease. It refers to a group of signs and symptoms that afflict long-term computer users, and mainly (but not exclusively) involves the eyes. Eyestrain is the most common feature of computer vision syndrome, and is caused by prolonged staring at the computer screen. In addition, muscle pain, headaches and other symptoms may also be present. In some cases, headaches may be accompanied by nausea.
Computer vision syndrome should not be confused with conditions such as motion sickness, epilepsy and migraines that can be triggered by playing certain video games. The symptoms of computer vision syndrome arise due to prolonged computer usage and lack of proper computer work habits (such as good posture, frequent breaks, and exercises).
Computer vision syndrome is becoming a widely known condition as the usage of computers continues to increase in our societies. It highlights the need for educating people in the proper practices of prolonged computer usage. Unfortunately, computer learning programs do not include this in their curriculum.
Signs and Symptoms
The following are the signs and symptoms associated with computer vision syndrome or computer vision sickness:
- Redness in eyes
- Blurry vision
- Double vision
- Dryness in eyes
- Eye pain or discomfort
- Tightness and pain in neck and upper back muscles
- Nausea (rare)
The intensity of the symptoms of computer vision sickness or syndrome vary among individuals. In some people, the symptoms are very mild, and occur only after several hours of staring at the computer screen. In others, the symptoms may be intense and can begin within a few minutes of starting work at a computer. In most cases, the severity of the symptoms of computer vision sickness is correlated with the amount of time spent working on the computer.
Nausea is not a common symptom of computer vision sickness or syndrome. However, it can occur due to prolonged computer usage. Nausea due to computer vision sickness should not be mistaken for nausea caused by motion sickness or migraines. Also, nausea in computer vision sickness is not psychogenic or imagined.
Read more on motion sickness.
Causes of Computer Vision Sickness Syndrome
The main cause of computer vision sickness or syndrome is believed to be muscle strain. However, the strain is not limited to the muscles in the eyes. Muscles in the neck, shoulder and head region are also involved. In addition, the way the images are displayed on a computer screen also adds to the eye strain.
Two types of muscles are involved in the proper functioning of our eyes. The movement of eyeballs is controlled by the extrinsic eye muscles. These muscles are involved in the proper positioning of the eyeballs. The second set of muscles, known as intrinsic eye muscles, are involved in controlling the amount of light entering the eye and in changing the shape of the lens in the eye.
These intrinsic eye muscles are involved in the process of vision. Prolonged staring at the screen can cause eye strain by affecting both the extrinsic and intrinsic eye muscles. The eye strain is a consequence of prolonged back and forth movements of the eyeballs within a small area, prolonged staring at a fixed distance, and prolonged exposure to high screen brightness at close distance.
Strain in head, neck, and back
The sitting posture adopted while doing prolonged work at the computer adds to the muscle strain. The muscles of the face, neck, shoulders, and upper back get strained by prolonged staring, squinting, clenching, and stooping. Poor back and neck posture strains the muscles of the neck, shoulders and upper back.
Images and brightness
The images on the computer screen are made up of discrete pixels, which can sometimes make it difficult to properly perceive the content on the screen. The lighting of the computer screen adds to the glare and the eyestrain. Computer vision sickness is not due to problems with vision. Pre-existing visual problems can increase the likelihood of getting computer vision sickness. They may also worsen the condition. However, computer vision sickness can occur even in individuals with perfect 20/20 vision.
Treatment of Computer Vision Sickness
No long term complications are known to be caused by computer vision sickness. However, the syndrome can severely limit daily functioning of the affected individuals. The following are some of the measures that can be useful for treating computer vision sickness:
- Use of anti-glare eyeglasses while working on a computer screen (even for people with no vision problems) can reduce eye strain.
- Existing vision problems should be corrected with prescription eyeglasses, contact lenses or refractive eye surgery (such as LASIK).
- Vision therapy to train eye and brain function can be helpful in treating problems with eye movements and focusing.
- Physical therapy may be used to relieve muscular strain in the neck, shoulders and upper back regions.
Prevention of Computer Vision Sickness
The best way to manage computer vision sickness is to take steps to prevent eye strain and muscle strain from occurring. The following are some of the preventive steps that can effectively prevent computer vision sickness or syndrome:
- While working at the computer, take a break every 20 minutes. During these breaks, focus your vision on far off objects (about 20 feet away) for 20 seconds and then return to the computer. This technique is known as the 20-20-20 rule.
- When our eyes are focused on something, we blink less. This is especially true when working at computer screens. Blinking more frequently can reduce eyestrain.
- The positioning of the computer screen in relation to the eyes can have a major influence on eyestrain. The screen should be at a minimum distance of about 25 inches from the eyes, and not more than 15°-20° below the eye level.
- Anti-glare eyeglasses should be used to reduce eyestrain while working at the computer screen.
- Screen brightness should not be set at the maximum.
- While working on a computer, one should sit upright on a chair with adequate back support.