An optical mouse uses camera technology and digital processing to compare and track the position of the mouse, rather than a ball and rollers used on older mice. This technology, first introduced by Agilent technologies in 1999, helps give users more precise performance without the maintenance and cleaning needed on older mice.

Inside each optical mouse is a small camera that takes more than a thousand snapshot pictures every second. A small LED (light-emitting diode) provides light underneath the mouse, helping to highlight slight differences in the surface underneath the mouse. Those differences are reflected back into the camera, where digital processing is used to compare the pictures and determine the speed and direction of movement. This differs from older-technology mice, in which a round ball rolled against a mouse pad to indicate movement.

Optical mice have a number of benefits over older technologies. One of the biggest benefits is that the elimination of the mouse ball, which frequently required cleaning to scrape accumulated grime of the ball or the rollers inside. As there are no moving parts in optical mice, almost no maintenance or regular cleaning is required. Another benefit is that digital processing often results in smoother, more accurate performance than prior technologies. Optical mice typically don't require a mouse pad and can be used on many surfaces, including those that are not entirely flat.

Optical mice are becoming increasingly common today in both homes and businesses. As technology and competition evolved, prices for optical mice have dropped to a $15-50 range, similar to ball-technology mice. There are typically no special PC requirements for optical mice and installation is usually as simply plugging the device in to the computer. A variety of optical mice can be found for both Windows, Macintosh and Linux platforms and are available with either PS/2 or USB plugs.