Figure 4. .

Bilateral sector prisms. (A) and (B) The prism bases are placed toward the blind side, shown here with base left. The prism apices are placed left of primary gaze by 2.1 mm. (C) Dichoptic simulated Goldmann diagram at primary gaze with these bilateral 20Δ sector prisms. The prisms have no effect, as they are entirely in the blind hemifield, so this is simply the same as a diagram of a left hemianope without prisms. The black triangle is included to indicate the prism orientation and apex location, but not its size. The arrowhead indicates the gaze point. (D) Corresponding percept diagram. It, too, is exactly the same as a diagram of a left hemianope without prisms.