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Photography of the fundus reflections of a point source of light from a human subject facilitates estimation of the refractive disparity about any desired axis, between the plane of focus of the subject’s eyes and that of the camera. The method employs a special attachment to a 35-mm reflex camera, consisting of a fiber-optic light guide mounted in the center of an array of pie-shaped cylinder lens sectors and placed in front of the camera’s wide-aperture lens. The light guide supplies a 1/4 second flash of filtered tungsten light of irradiance less than 1 μW/cm^2 at the corneas of the subject, who is seated 1–2 m distant. The reflected light emanating from the subject’s pupils is transformed by the array of cylinder lenses into a star-shaped pattern at the film plane; the lengths of the arms are proportional to the dioptric disparities about the corresponding axes. Theoretical intensity distributions of star patterns for spherical and …