Search results
Results from the WOW.Com Content Network
The formula for vertex correction is = (), where F c is the power corrected for vertex distance, F is the original lens power, and x is the change in vertex distance in meters.
Fixation disparity. Fixation disparity is a tendency of the eyes to drift in the direction of the heterophoria. While the heterophoria refers to a fusion-free vergence state, the fixation disparity refers to a small misalignment of the visual axes when both eyes are open in an observer with normal fusion and binocular vision. [1]