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Clinical Care and Practice Advancement
Computer Vision Syndrome (CVS)

Computer Vision Syndrome Symptoms



Many of the symptoms of CVS (see Table 1) can be broadly classified as "asthenopia." Most of these symptoms are also associated with other forms of near work. Neck and/or backaches are listed as a symptom of CVS since the eyes lead the body. Computer workers will often assume awkward postures in order to position their eyes so that they can perform their work - resulting in these musculoskeletal symptoms. This can be the result of a poorly designed work station, assuming awkward postures due to using spectacles which are improperly designed for the task or due to making accommodations for a particular eye/vision disorder.

Table 1:
Computer Vision Syndrome (CVS) Symptoms

Eyestrain (Non-Specific Ocular Discomfort) Blurred Distant Vision
Fatigue Dry or Irritated Eyes
Headache Neck and/or Backaches
Blurred Near Vision Diplopia (Double Vision)

In most cases of CVS, the clinician is able to establish a visual diagnosis for the symptoms being experienced (see Table 2). There are numerous accommodative disorders (e.g., decreased amplitude or infacility of accommodation) and binocular vision dysfunctions (e.g., phoria, strabismus) that can clearly cause the symptoms. Uncorrected or improperly corrected presbyopia (improper add/or spectacle design) can also result in symptoms. Hyperopia can result in visual symptoms - especially in near workers. Uncorrected astigmatism can also cause symptoms because of the acuity demands of the task. In some cases myopia can cause a blurred view of the computer screen and/or awkward posture. There is also some evidence to indicate that near work causes the development of myopia in some individuals. A dry eye condition is one which can be exacerbated by computer work due to staring, elevated gaze angle, decreased blinking, and a low humidity environment.

Each of the CVS diagnoses presented in Table 2 can be treated - usually with a good prognosis for eliminating or reducing the presenting symptoms.

Table 2:
Computer Vision Syndrome (CVS) Visual Diagnoses

Accommodative Disorders Refractive Errors
Presbyopia Hyperopia
Binocular Vision Dysfunctions Astigmatism
Dry Eyes Myopia

CVS symptoms occur as a result of visual interaction with a task (the computer display) which stresses the visual system. The occurrence of symptoms depends upon the magnitude of any existing visual disorder as well as the demand level of the task. The task demand level can be dependent upon many variables. There are particular environmental factors associated with work at a computer which make it more visually demanding than other near point tasks. (See Table 3)

Table 3:
Environmental Factors of Computer Workstations

Contrast and resolution of the display Room lighting
Viewing distances and angles Sustained viewing
Adjustability of workstation

Appropriate diagnosis and treatment of existing vision problems and control or elimination of environmental factors can effectively reduce the symptoms associated with computer vision syndrome.