Apparatus for measuring accommodation of a lens in an eye includes a target, a Badal lens, and a viewing aperture, where the Badal lens and the viewing aperture are positioned so that when the target moves towards or away from the lens, the apparent size of the target remains constant to a subject looking...http://www.google.com/patents/US20040041980?utm_source=gb-gplus-sharePatent US20040041980 - Apparatus and methods for measuring accommodation of a lens in an eye
