Clinical refractive instruments

摘要

A clinical refractive instrument is described for adjusting dioptric power according to three orthogonal axes. The instrument includes a viewing aperture, a plurality of spherical lenses and a pair of cylindrical lenses. The plurality of spherical lenses are adjustable such that a selected spherical lens may be aligned with the viewing aperture. The pair of cylindrical lenses are operative to produce a combination of astigmatic power elements J₀ and J₄₅. Each of the cylindrical lenses capable of being independently rotated, and the pair of cylindrical lenses may be super imposed with respect to each other and aligned with the viewing aperture and the selected spherical lens. Methods for using and controlling the instrument are also described.