Three-dimensional visual stimulus deflector.

A 3-D visual stimulus deflector has been designed so that a subject can view any stimulus pattern or object through it, and the pattern (up to 25 degrees in diameter) can be moved over a range of 40 degrees horizontally and 30 degrees vertically. The optical distance of the object being viewed can be changed over a 15-diopter range, while the brightness and visual angle subtended by the object remain fixed. Further, the observer can view the object through a pupil of any desired shape and transmittance. Horizontal and vertical movements are independent, with time delays of 1 msec and a response range from dc to 200 Hz. Focus change is independent of lateral field motion and has a time delay of 12 msec and a maximum slewing rate of approximately 40 diopters/sec. Two such devices can be aligned side by side in a binocular configuration for independent 3-D control of the fixation of each eye.