Binocular fields with lateral-eyed vision

A simple geometrical model is constructed of the binocular field in animals with laterally directed eyes (such as the pigeon). Height and width are derived as a function of elevation, for eye-centred and for cyclopean co-ordinates. Stereoscopic vision in the frontal field is considered, and it is pointed out that convergence movements can facilitate stereopsis even in an afoveate periphery.