[Skip to Content]
Access to paid content on this site is currently suspended due to excessive activity being detected from your IP address Please contact the publisher to request reinstatement.
[Skip to Content Landing]
May 1968

Entoptic Visualization and Impletion of the Blind Spot

Author Affiliations

Long Beach, Calif
From the Department of Surgery, Section of Ophthalmology, Veterans Administration Hospital, Long Beach, Calif. Dr. Pearce is presently at St. Mary's Long Beach Hospital, Long Beach, Calif.

Arch Ophthalmol. 1968;79(5):589-594. doi:10.1001/archopht.1968.03850040591019

The blind spot of Mariotte can be visible subjectively for as long as 15 seconds at low luminances, and also in the dark. When the adaptation of any part of the visual system is unmatched to the stimulus, either a dark disc scotoma appears on a lit field, or a bright disc scotoma appears on a dark field. Often there is a border contrast phenomenon thought to be indicative of lateral inductance in the cortical fourth order neurons. The scotoma is most slowly filled up at low luminances, and is not perceptible with bright fields unless these have been preceded by prolonged dark adaptation. The initial impletion depends upon the contralateral retina; final "matching" impletion may be made by the complex cells, fifth order, or higher, on signals from the ipsilateral retina, and at the same time supression of the contralateral "nonmatching" signals.