Face-form frames

Face-form frames may be appropriate for sunglasses but present many problems if used for prescription lenses especially when the power is strong. Angling the lenses affects the power and location of the cylinder axis and makes it difficult to attain the right P.D. The problems of mounting the lenses in the frame are magnified. Angling also generates unwanted sphere and cylinder in the periphery as well as distortion. These effects can be measured and even calculated ahead of time and cannot be dismissed lightly. The increased field of view is not needed.