Computer vision syndrome (CVS), also referred to as digital eye strain, describes eye and vision-related problems that result from prolonged computer, tablet, e-reader and cell phone use.
Many individuals experience eye discomfort and vision problems when viewing digital screens. The level of discomfort appears to increase with the amount of digital screen use.
The main visual symptoms reported by visual display terminal (VDT) users include eyestrain, tired eyes, irritation, burning sensation, redness, blurred vision, and double vision, thus termed the phrase ‘computer vision syndrome’ (CVS).
Vision problems and symptoms associated with the use of the eyes are the most frequently occurring health problems among VDT users. CVS not only causes pain and discomfort to the individual, but also reduces overall efficiency by reducing the time that a person can effectively work.
Majority of VDT patients had symptoms that were different than other near-point workers, especially as related to glare, lighting, and spectacle requirements.
Greater frequency and severity of symptoms were also noted. One study shows higher degree of meibomian gland dysfunction (MGD) in symptomatic computer users than in computer users who have lesser degrees of ocular surface complaints.
Occupational Safety and Health Administration of the US Government (OSHA) has defined CVS as a ‘complex of eye and vision problems that are experienced during and related to computer use; it is repetitive strain disorder that appears to be growing rapidly, with some studies estimating that 90% US workers using computers from more than three hours per day experience CVS in some form.’
The American Optometric Association (AOA) has defined CVS as ‘a complex of eye and vision problems related to activities, which stress the near vision and which are experienced in relation or during the use of computers.’
It has now been concluded that CVS is characterised by visual symptoms which result from interaction with a computer display or its environment. In most cases the symptoms occur because the visual demands of the task exceed the visual abilities of the individual for comfortable performance of task.
Office work involves a range of activities including typing, reading, and writing. Each activity was adequately varied in the requirements of posture and vision.
Computers have combined these tasks to where most can be performed without moving from the desktop, thereby improving quality, production, and efficiency. The popularity and affordability of personal computers with the internet capabilities at home introduced more computer users.
Studies have not clearly indicated a negative effect on computer user due to radiation levels from VDTs.
VDTs are known to emit many types of radiation, including soft X-radiation, optical radiation, radiofrequency radiation, very low frequency radiation, and extremely low frequency radiation. Most women in offices, who work with VDTs, do not increase their risk of miscarriage.
It may well be that high computer usage raises the number of dry eye sufferers and/or increases the severity of symptoms, but studies have not produced any direct comparison of groups that would allow us to conclude that computer use bears a long- term causal relation to ocular surface disease.
There needs to be more prospective studies to elucidate direct relationship between ocular surface disease (e.g. MGD) and CVS.
Source: National Health Survey