University of Iowa Health Care

Ophthalmology and Visual Sciences

Paradoxical Pupillary Response

Contributor: Matthew S. Ward, MD

Here is a case of congenital stationary night blindness with a paradoxical pupillary response. One would expect the pupils to dilate when the light is OFF and constrict when ON, but in this and other inherited retinal disorders, the opposite can be observed. The cause of this phenomenon is unknown, but there is speculation it has to do with faulty "gain" control with regard to the light response.

last updated: 2/5/2013
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