[The effect of lens opacities on the visual field (author's transl)].

The stray light effect on the visual field was quantitatively studied in normal subjects under experimental conditions. Stray light comparable to that caused by lens opacities was produced by means of selective occluders or diascleral illumination. The results derived from this model were compared with the statistical evaluation of the visual fields of 123 eyes with glaucoma followed for a minimum of 10 years. As expected lens opacities resulted in a concentric constriction of the peripheral fields and a loss of the inner isopters. The light difference sensitivity as determined by static perimetry was generally reduced preferentially in the central fields. These calculations provide a measure to anticipate the degree of lens opacifications from a depressed visual without knowledge of the visual acuity.