The Effects of Computer Use on Eye Health and Vision

The increased use of computers in the workplace has brought about the development of a number of health concerns. Many individuals who work at a computer report a high level of job-related complaints and symptoms, including ocular discomfort, muscular strain and stress. The level of discomfort appears to increase with the amount of computer use.Visual discomfort and related symptoms occurring in computer workers must be recognized as a growing health problem. The complex of eye and vision problems related to near work experienced during computer use has been termed "computer vision syndrome".
Vision problems experienced by computer operators are generally only temporary and will decline after stopping computer work at the end of the day. However, some workers may experience continued impaired or reduced visual abilities, such as blurred distance vision, even after work. If nothing is done to address the cause of the problems, they will continue to recur and perhaps worsen with future computer use. Work that is visually and physically fatiguing may result in lowered productivity, increased error rate and reduced job satisfaction. Therefore, steps should be taken to reduce the potential for development of stress and related ocular and physical discomfort in the workplace.

One of the most significant environmental factors affecting computer work is lighting. Surveys indicate that many computer users report problems with general workplace lighting, glare and images reflected on the computer screen. Many problems related to lighting may be caused by the introduction of computers into offices where the lighting was originally designed for traditional desk top work. The lighting is designed on the assumption that workers will perform tasks requiring their lines of sight to be depressed 20 to 40 from the horizontal. In many situations, however, computers are placed so that viewing occurs at or even above horizontal eye level.

Bright lights in the peripheral field of view may cause discomfort glare. Windows, overhead fluorescent lights and desk lamps often contribute to this problem. These bright light sources can be controlled with proper workstation and/or room design and arrangement. An acceptable lighting level may require a compromise between that amount of light needed to enhance computer screen visibility and reduce reflections and glare and that needed to perform other office reading and work tasks. Older individuals will generally require more light than younger individuals to perform the same tasks comfortably. Workers over 50 years of age require twice the light levels of young adults for comfortable work

The brightness of the screen and the surrounding room should be balanced. For dim or dark background screens this often requires using lower light levels than are used for other types of office tasks. However, lighting requirements will vary with the task. More lighting may be needed when other source documents are also viewed. In general, lighting levels between 200 and 700 lux (approximately 20 to 70 foot candles) measured at the workstation are recommended. More than 500 lux will usually be needed only to read poor quality documents. This additional lighting may be accomplished through the use of specific task lighting.

The use of computers is associated with a decreased frequency of blinking and an increased rate of tear evaporation, each of which contributes to dry eyes.The use of artificial tears can provide relief from dry eye symptoms in some cases. In addition, the width of the palpebral fissure, and hence the exposed ocular surface area, can be decreased by placing the computer monitor at a lower height.