Fig. 11. Hemifield slide—effects on reading. In patients with bitemporal hemianopia, episodes of binocular misalignment can occur in both vertical and horizontal directions. These misalignments between the nasal hemifield of the eyes are illustrated on the right side of the diagram. The effects of such misalignments on the reading of a paragraph are shown on the left side. The result is a type of “secondary alexia,” that differs from the cerebral mechanism for pure alexia illustrated by Dejerine.