These vergence prisms quickly screen for binocular vision. Use these to get the patient to cycle between the two prisms up to 15 cycles per minute. Use at 16″ (40 cm) with a 20/30 near point line. Prisms are 12D base-out and 3D base-in and 1.5″ high (38mm).
The Vergence Facility Prism is available in :