Long-term changes of orienting behavior in cats with artificial divergent strabismus.

Orienting behavior was measured in two monocular spatial localization tasks in normal cats and in cats with artificially induced monocular divergent strabismus. Immediately, and for several weeks after the operation, cats made large "past-pointing errors" with the deviated eye in a direction opposite to the misalignment. These errors were replaced later by "over compensation errors" in the same direction as the strabismus deviation, which persisted for many months after the operation. Over-compensation did not occur when the non-deviated eye was sutured in early life. Electrophysiological measures like grating VEP and A17 single unit responses demonstrated the dominance of the non-deviated eye in the strabismic cats. It is suggested that long-term binocular exposure may lead to a reorganization of visual direction for the deviated eye in divergent strabismus.