Protect Your Eyes from CVS

Protect Your Eyes from CVS

Do you have eyestrain, dry or irritated eyes, and blurry vision after hours at the computer? You may be suffering from Computer Vision Syndrome or CVS. Software and graphics engineers, design engineers, writers, as well as those who surf the internet for extended stretches of time - all fall under the high-risk group for CVS. Our colleague Satish Kumar shares some important tips on how CVS affects your work, how to prevent it, and relieve symptoms.

What causes CVS?

CVS is caused by a combination of factors as described below:

Continuous focusing of eyes: The computer user has to constantly shift the focus of his eyes between the monitor screen, the keyboard, documents, and the surroundings. Each of these areas has a different level of brightness. Frequent movement of the eyes and continuous focusing put high degree of strain on the intrinsic and extrinsic muscles of the eyes.

Glare: Glare may be due to sources of direct light in the field of vision or reflected light from polished surfaces near the work station. Glare may reduce visibility and productivity and also cause annoyance, discomfort, and distraction.

Drying of tear film: The surface of the eye is covered by a tear film, which is spread by blinking the eye. Computer users have a tendency to stare at the monitor with eyes wide open, which results in increased evaporation of the tear film. The blink rate of the eye reduces while staring attentively at the monitor. This leads to dryness of the eyes. The problem is exacerbated by the use of air-conditions in areas with dry climates as it accelerates the evaporation of the tear film. In addition, use of contact lenses may also aggravate dryness of the eyes.

Flawed working habits and postures: While working on computers, the muscles of the eyes, neck, and shoulder are strained by constant upward gaze and faulty body posture due to unsuitable location of documents and other reference materials.

CVS develops over a period of time. The vision disorders may initially manifest as localized fatigue, which may subside when the person stops working on computers. However, the symptoms may return if the work is resumed.

Prevention and control

By recognizing the hazards of working continuously on a computer, and by following certain tips, CVS can easily be prevented or at least controlled. Given below are some tips on prevention and control:

Ergonomic measures: The postures during work, the duration of work, job profile, ocular health status, and recreational habits are all important factors.

• The eye-to-screen distance should be 25 inches or more
• The eyes work best with a light downward gaze
• The viewing area of the screen should be about 15-50 degrees below eye level
• Regular pauses for rest help in delaying the onset of eye fatigue. The frequency and duration of rest pauses would depend on the nature of task and the individual attributes of the computer user.

Use of computer glasses: Many computer users may require special glasses, which are designed to accommodate the unique viewing distances and angles for computer-related work. Since the user has to focus his or her eyes at an intermediate distance (neither distant nor a typical viewing distance), these glasses would be different from those that may be used for other visual needs.

Lighting: The quality of light in the work environment should be adjustable. 

• Natural sunlight is the most comfortable to the eyes
• The distribution of light in the work environment should be 3 times the level of the ambient light. Only then the eye muscles can relax while the user looks away from the computer monitor
• The lighting at the workstation should be adjustable as per the user's height and should not be directed at the monitor.

Prevention of glare: It is important to control or at least minimize the glare of the computer screen.

• Diffuse lighting reduces the sources of glare in the field of vision
• Only filtered light should be allowed into the room by using curtains and drapes
• The computer monitor should be placed at right angles to the window
• Glare can also be minimized by using keyboards with anti-glare matte finish and by painting the walls with a non-reflective medium-to-dark paint.

Prevention of dryness of eyes: To prevent the problem of dryness of the eyes, the computer user should blink frequently, purposely, and consciously. During rest pause, the eyes should be closed and rolled behind closed eyeballs. Alternatively, the eyes may be closed and rolled tightly for few seconds during rest pauses. If necessary, the computer user may use artificial tear substitutes to re-wet and lubricate the eyes.

Reducing evaporation of tear film: The following action helps to reduce the evaporation of the tear film.

• Working with downward gaze (by lowering the level of the computer screen). This decreases the exposed area of the eyes and diminishes the evaporation of tears
• Using spectacles with side panels
• Avoiding direct airflow in the direction of the eyes
• Using humidifiers along with air-conditions in the hot and dry climates.

Now that you know all about CVS, follow these useful tips and say good-bye to  dry, irritated eyes, eyestrain, and blurry vision.