a ball in a socket; and since the frame of the glasses is in a fixed relationto the head, the eyes will use ditferent portions of the lens. It is thus apparentthat the correction of the refraction of an eye, when directed straight forward,is only a small part of the functions of a perfect eye lens.…
Lenses · Eyeglasses
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
