摘要 |
A subjective refraction technique uses a plane wave light source including substantially a point as a viewing target. By finding such end points the process leads to an aberration-corrected vision. A defocus corrector assembly (DCA) includes a lens that is moveable along an optical axis between a patient's eye and the point light source for adjusting defocus power until the patient indicates that the blurry image has become a relatively focused line image. An astigmatism corrector assembly (ACA) which is capable of continuously variable in its amplitude is provided including a pair of astigmatism plates for adjusting astigmatism power and axis angle. The ACA is adjusted until the patient indicates that the line image has become a substantially round image. A reference marker provides displayed items including a sweep line overlapping at the point source and having an orientation which is adjustable. |