Computer focus has unique visual demands that are unlike with other activities, so that a prolonged computer use may bring eyestrain and fatigue more easily. Some of the people under 40 can not remain accurately focused on the computer screen for a long period, or get tired from the frequent switch between the screen and the keyboard. Presbyopia on people above 40 may also cause CVS symptoms such as blurry vision and headache.
The simplest way to address CVS (Computer Vision Syndrome) is the special computer glasses, which are superior to regular prescription glasses. All those commonly used prescription glasses such as reading glasses, bifocal glasses and single vision glasses for myopia are not designed to suit computer use. The reason is that computer focus needs the intermediate zone of vision, which is closer than distance vision and farther than near vision. Even trifocals and progressive glasses can only cover a small portion of this area.
The University Of Alabama School Of Optometry has conducted a research of participants between 19 and 30, who either wear computer glasses or non-corrective glasses. Researchers recorded the performance of these people in finishing font tests. The result showed that people with computer glasses had higher work productivity than the other individuals.
Computer glasses have special designs that are not suitable for regular wear. A single vision lens with special power provides both the most comfortable computer vision and the largest vision field. This type of computer lens design reduces the risk of eyestrain, blurred vision and unnatural posture. For people with presbyopia, occupational progressive lenses or lined trifocals with larger intermediate zone provide the right solution. But they are not suitable for driving since the distance zone is narrowed. Occupational bifocal lenses offer a top lens part for intermediate vision and a bottom part for near vision.
Eyestrain can also come from bright office lighting. Anti-reflective coating can be used to reduce glare and UV absorbing coating can be used to block blue light emitted by fluorescent lights.