Computer glasses are prescription glasses that designed to wear while doing computer work. They allow you to focus your eyes on the computer screen, which is farther away than reading material is normally held. There are other activities such as playing piano or shooting that also require a similar custom fitting. These specialty glasses called "task-specific" are designed to meet the visual needs of the activity.

General purpose bifocals are not designed for computer work. They force the wearer to tilt the head back in order to focus on the screen while looking through the lower segment of the bifocal lenses. Such a forced position can cause neck and shoulder pain and it can also cause arm and low back pain.

Depending on the individual's vision and type of work, there are several options while selecting computer-specific glasses, such as:

Monofocal

Monofocal or single-vision glasses provide the appropriate optical correction for the working distance between the screen and the computer user's eyes. This option allows users to view the whole screen with a minimum up-and-down head movement.

The disadvantage of this option is that both distant objects and reading materials that are closer than the computer screen will appear blurry.

Bifocal

Bifocal glasses can be prescribed so that the upper segment is set up for the screen distance and a lower segment for work that is closer than the screen ("reading distance").

The disadvantage of this option is that objects farther away than the screen are blurry. Bifocal lenses also distort images of objects in the peripheral zone of vision. Segmented lenses like bifocals and those mentioned below have a smaller area for viewing the screen. This means more up-and-down head movement is required to view all parts of the screen.

Trifocal

Trifocal glasses have lenses that combine a segment for far vision (upper), another for near vision (lower / bottom) and a third one for vision at the screen distance (middle, between the far and near segments).

The disadvantage of using trifocal lenses is a limited continuity of vision. Distortion in peripheral vision is more pronounced than in using bifocals.