Visual field defects due to opacities in the opitcal media.

The object of this paper is to draw attention to the fact that asymmetrical opacities of the optical media, especially of the posterior layers of the crystalline lens, may cause asym- metrical defects in the visual field, and that such defects vary with the diameter of the pupil. Opacities situated in the posterior layers of the lens cause a defect in the visual filed on the opposite side, while opacities in the cornea cause a defect in the visual field on the same side. The optics of these two situations are explained in simplified diagrams below in Figs i and 2.