Comporison of Three Methods for Ropid Determinotion of Threshold Controst Sensitivity

(referencing the active electrode to the forehead where a small but recordable response is also present) combine to reduce the PERG amplitude. In such situations it is less likely that the spread of potential will be strong enough to be recorded as a referred response. On the other hand, if, in a binocular viewing situation, one records a normal PERG from an eye that has no light perception, the possibility that a referred PERG may have been recorded inadvertently must always be entertained.