A computer input device, such as an electronic mouse, having an optical projection system. The optical projection system is configured to project an image onto a housing wall surface, which may be on a side, top, or rear of the device. In one arrangement the optical projection system includes a light source, an image forming light blocker and optics. The optics may be collimating or non-collimating. In another arrangement the optical projection system may include an active LED matrix display. This system enables a use to personalize and/or customize his or her computer input device. Additionally, it permits the device to serve desirable notification functions if one or more of various events have occurred in a computer application being run on the computer. An example of event for notification includes the receipt of a message in a communications program such as an e-mail message.