Optical feedback is the optical equivalent of acoustic feedback. The feedback occurs when a loop exists between an optical input, for example, a videocamera and a television screen or monitor. (A simple example of optical feedback is an image cast between mirrors.)

In this GIF movie, and the JPG still image examples (right), light from a candle is received by a videocamera, amplified and then sent by cable to a monitor projecting electron beams on the inside of the monitor screen. The image on the monitor is then captured by the videocamera again, and fed back to the monitor in a continuous loop.

The original light source, in this case from the candle, can then be extinguished, while the feedback loop continues. For each loop the image is doubled and the image interferes with itself. The electronic loop moves with near light speed, but as the resulting image is projected onto the phosphor dots on the inside of the screen the speed is stopped for as long as allowed by the time the phosphor points glow, and thus creating a "queue" of illuminated dots on the screen.

The resulting images depend on different camera and monitor settings, such as light amplification, contrast, distance, angle and physical vibrations. Optical feedback can be combined with music, or other sound sources, to influence the image loop.