OCULAR ROTATION FACTOR AND ORIENTATIONAL DEMAND WITH ASTIGMATIC LENSES

Ocular movements required in most visual functions are affected by len ses in front of the eye. Fundamental to an understanding of these move ments are concepts such as the ocular rotation factor and the ocular o rientational demand. In this paper the ocular rotation factor for thin spherical lenses is generalized for astigmatic lenses. A compact matr ix equation is obtained for the orientational demand in the case of su ch lenses. The equations are satisfactory in ordinary situations but t hey break down under certain circumstances. Equations are derived for these special circumstances in particular and also for all circumstanc es in general.