ABSTRACT
Electroretinography is a recording technique which is used to assess the electrophysiological function of the retina. Electroretinography of human subjects is usually performed on conscious individuals with the aid of a head-rest, whereas in unco-operative animal subjects anaesthesia is required. The electroretinogram (ERG) is usually recorded from the surface of the cornea. The recording electrode used can be a corneal contact lens type or one which is inserted into the lower conjunctival sac/looped over the lower eyelid. Cone ERGs may be recorded using flashes of light superimposed on a background light which has the effect of light-adapting the eye and diminishing or abolishing the rod response. Cone responses are frequently recorded using a flickering light stimulus. The ERG signal is amplified by a pre-amplifier and waveforms are displayed on an oscilloscope where they may be photographed or stored on computer disk.
