A perceptible fluctuation in the intensity of a computer monitor's display produced during refresh cycles when the refresh rate exceeds the persistance of the phosphors coating the back of the screen. Flicker is also observed in a television or video picture when the two fields of a particular frame are not properly synchronized. A particular type of flicker—called interlace flicker—is a condition that affects monitors whose image is formed by means of interlacing. See Interlacing and Interlace Flicker.