5176   Alpha Base Out Unit

The basic vision therapy unit for exophoria (overconvergence or being "wall eyed") and useful in cases of premature presbyopia, a diminished ability to focus usually due to age. Keystone View base-out units simulate normal environmental demands on the eyes and can aid patients in accepting new lens prescriptions, particularly bifocals.

• Includes 12 targets, half of them jump-fusion targets, and a patient's manual


• Maximum prismatic effects at infinity are 30 BO and 0 BI.