Definition : Ophthalmic instruments designed to measure critical flicker frequency (CFF), the transition point at which the visual sensation of an intermittent light (i.e., flicker) disappears, becoming stable for the observer, as indicated by the patient response at the points (i.e., the frequency value) at which he or she can perceive flickering and can no longer perceive flickering. The devices usually consist of variable frequency light sources, digital controls, an LCD display, and eyepieces. Flicker-fusion units are intended for assessment of a variety of problems (e.g., trauma, drug effects, alcoholism) as they are reflected in the visual function.
Entry Terms : "Ophthalmic Measuring Instruments" , "Measuring Instruments, Ophthalmic"
UMDC code : 11736