摘要 |
Optical characteristics, including vision defects, of optical systems, such as the eye, are measured using a collimated beam from a diode laser focused at a position relative to the eye other than the retina for providing a finite source of secondary radiation on the retina of the eye, the image of which is close to a desired diffraction-limited spot. The secondary radiation is reflected back from the retina as a reflected wavefront of radiation that passes through the eye and is directed onto a wavefront analyzer where distortions associated with the reflected wavefront are measured. By focusing on the cornea through a long-focal-length lens and thus converging the beam through a small angle, as opposed to focusing a collimated light onto the retina, the need for lenses or lens combinations and the time required to adjust such to accommodate the different visual characteristics of each patient is eliminated. |