What Is an Optical Trackball?

An optical trackball is a computing device that allows the user to select or navigate through computer content.

Some optical trackballs also contain a scroll wheel to for ease of scrolling through web sites and documents.

The ball portion of the optical trackball is covered with dots arranged in a pattern.

As the user manipulates the ball with his fingertips, infrared optical sensors read the movement of the dots and send the data to the computer. This feature may allow for a more precise tracking of movements than non-optical trackballs, since non-optical sensors simply read the rotation of the ball on two axes.

An additional benefit of optical trackballs over their non-optical counterparts is that they detect movement optically; dust, dirt and skin oils do not interfere with the detection of movement. However, the ball and sensors should be cleaned on a regular basis according to manufacturer's instructions to ensure optimal functioning.

Trackballs designed specifically for left-handed users are not readily available, so left-handed users typically either choose an optical trackball that may be used by the left hand or simply adjust to using the trackball with their right hand.

Most of the trackballs found on portable computers and computer keyboards are not optical, although there are some keyboards that do have optical trackballs.