By Eyecare NGOverview | Symptoms | Causes | Diagnosis | Management
Computer vision syndrome (CVS) is a group of eye and vision problems resulting from the extended use of computers and digital devices like cell phones. It is also known as digital eye strain and it is characterized by a number of non-specific symptoms that tend to worsen as the length of time spent on computers and other digital devices increase.Increased computer use places more burden on an individual’s visual system resulting in symptoms like eye pain, headache, burning sensation and more.
Computer vision syndrome affects people of all ages including children. However, the effect of the computer on the eyes varies from one person to another depending on each person’s tolerance level for extended visual tasks.
Computer vision syndrome has become a cause for concern as classrooms and offices are going digital replacing blackboards and papers with digital screens and computers. Students these days engage with the computer for extended periods resulting in an increased number of computer vision syndrome cases among school children.
- Eye pain
- Burning sensation
- Feeling of discomfort
- Double vision
- Neck and shoulder pain
- Blurred vision
- Gritty sensation
Computer vision syndrome is caused by the increased demands placed on the eyes during the use of computers and other digital devices.
Compared to working with papers, the eye does more work with digital devices. The eyes move back and forth, adjust to changes on the screen as it is scrolled up and down and also tries to cope with the glare and flashes from the screen. These demands on the eyes cause stress when they go beyond what the eyes can cope with. The stress on the eyes often gets worse if certain factors such as eye problems and unfavourable habits and environmental conditions are present.
Factors that can contribute to the development of computer vision syndrome include:
Uncorrected refractive errors, presbyopia and binocular vision anomalies: Uncorrected refractive errors (such as long-sightedness and astigmatism), presbyopia and binocular vision anomalies (like convergence insufficiency and accommodative insufficiency) under normal circumstances cause visual symptoms such as blurring, headaches, tearing, double vision and more. These visual symptoms usually get worse during computer use leading to eye strain.
Poor room lighting and reflections from the screen: Bright overhead lights and sunlight from the windows, for instance, can reflect on the screen causing glare and discomfort to computer users.
Inappropriate positioning of workstation: Placing the screen at a wrong distance (too far or too near) or viewing it from an inappropriate angle due to the height of the table or chair can cause discomfort, fatigue and neck, shoulder or back pain.
Time spent on the computer: The longer an individual spends looking at a computer screen, the more likely he will develop eye strain.
Decreased blinking: While working at the computer, people tend to blink less causing the surface of the eye to dry out quickly. Dry eyes cause symptoms such as pain and burning sensation which can result in eye strain.
To diagnose computer vision syndrome, the eye doctor will perform a comprehensive eye examination which would normally include the following:
History taking: The diagnosis of computer vision syndrome starts with a detailed case history to determine an individual’s main complaint, other symptoms, visual tasks the person is involved in, habits and environmental conditions.
Visual acuity: This measures how well an individual can see at far and near.
Refraction: This detects and measures refractive errors. This is important because uncorrected refractive errors are major factors in computer vision syndrome.
Binocular vision assessment: This involves assessing the ability of the eyes to work together (eye teaming), focus on an object (eye focusing) and follow an object (eye tracking). Any deficiencies in these functions will be determined during the assessment.
External and internal examination: These are done to determine the state of the structures of the eye, outside in and from front to the back. Assessment for dry eyes is also done.
Corrective lenses: Corrective lenses are usually prescribed if refractive errors or presbyopia is found to be causing eye strain. It is important that the lenses are appropriate for the individual’s working distance. Lenses meant for reading at near may not be good enough for computer use because the reading distance and computer distance are usually not the same. There may also be a need for special lenses with coatings such as anti-reflective coating and blue filters that help make computer use more comfortable.
Vision therapy: People with binocular vision anomalies that cannot be corrected with glasses or prisms may benefit from vision therapy. Vision therapy can improve the capacity of the eyes to work together with less stress.
Dry eye treatment: Dry eye treatment is required if computer vision syndrome is caused by dry eye syndrome. Treatment usually depends on the cause of dry eyes. Most cases, however, benefit from the use of lubricating eye drops. Learn more about dry eye treatment.
Correct arrangement of work area: It is necessary that the work area is properly arranged to enable a computer user maintain the right sitting posture while working or looking at the computer. The computer screen should be positioned in such a way that the eyes look downwards at it from a comfortable distance (usually about 50 – 100cm for most people). The screen should be faced away from light reflections to avoid glare. The material the user is looking at while typing should be placed above the level of the keyboard and below the monitor. It can also be placed beside the monitor using a document holder, this prevents the constant moving of the head and the eyes from the document to the screen. The chair should be adjusted such that the feet rest flat on the floor and the table at a level that is comfortable for the user.
Adjustment of room lighting: To avoid glare, room lighting should be done in a way that minimizes reflections on the computer screen. Covering the windows with blinds eliminate sunlight and other exterior light reflections. Using bulbs with low wattage minimize interior light reflections. Antiglare screens can also be placed in front of the computer screen especially in situations where the reflection from light sources cannot be controlled.
Adjustment of computer screen settings: Eye strain can be minimized by adjusting the computer screen settings (such as contrast, intensity and brightness) to levels that are comfortable for the user.
Blinking regularly: Computer users have a tendency to blink less while looking at the screen. Making a conscious effort to blink regularly can help minimize eye strain associated with dry eyes. This is because blinking prevents dryness by spreading tears and keeping the surface of the eyes lubricated.
Use of darker backgrounds at night: Changing the screen background to a darker one at night reduces the reflection of light from the screen into the eyes; thereby making computer use at night less stressful for the eyes.
Rest: Rest relieves the eyes of the many symptoms that may arise as a result of computer use. Applying the 20:20:20 rule can help the eyes get some rest during extended computer use. The 20:20:20 rule recommends that for every 20 minutes of computer use, you should take 20 seconds breaks and look at something else at about a distance of 20 feet away from you. Taking breaks to stretch the legs, arms, neck and shoulder can help prevent muscle spasm and cramps.