Effect of area and intensity on the size and shape of the electroretinogram; exclusion of stray light effects.

SINCE Adrian and Matthews (1928) showed that the latent period of the optic nerve discharge can be influenced by the size of the area stimulated, the effect of area on the electroretinogram has been confirmed by a number of workers (Granit, 1933; Creed and Granit, 1933; Fry and Bartley, 1935; Boynton and Riggs, 1951). The size and shape of the electroretinogram can be influenced in the same way by increasing the stimulated area as by increasing the intensity ofthe stimulus. Fry and Bartley (1935) stated that the effect of areawas due almost entirely to stray light; they believed the effect of the focal area to be small. They performed the following experiment on the intact rabbit eye: