Prism is a measure in prism diopters. The most common application for this is the treatment of strabismus. In
eyeglasses, prisms are used primarily for double vision, positional correction, or convergence correction.
By moving the image in front of the deviated eye, double vision can be avoided and comfortable binocular
vision can be achieved.
A lens which includes some amount of prism correction will displace the viewed image horizontally,
vertically, or a combination of both directions. Ublins is able to accommodate prism corrections with a
range of 0 to 5.00 diopters in any direction or combination of directions. In an eyeglass prescription, the
base is typically specified as up, down, in, or out. Prism corrections are available only for single-vision
prescriptions, not progressives.