Blinks, negative flashes, and visual responses

Evoked visual responses that were triggered by spontaneous blinking were recorded from the human subject. Although their waveform resembled that of conventionally recorded responses, two differences were noted: there was an early potential that was seen only with blink responses, and the late negative potential was smaller than that seen with conventional recording. Off- and on-components were seen in the blink responses, and these were compared with those produced by switching the stimulus off and on. The amplitudes of all of the components increased with stimulus intensity. The results suggest that blinking may play a role in vision, per se, as well as acting to protect the cornea.