METHODS FOR OBJECTIVELY DETERMINING THE VISUAL AXIS OF THE EYE AND MEASURING ITS REFRACTION

摘要

Provided are methods for determining an axis of best vision of an eye or for objectively determining a visual axis of an eye and for making the most accurate measurement of refraction. Generally, an optical measuring device or instrument projects laser beams into the eye during a scan. Positions of the projected beams are detected and measured on the retina to produce a set of projections. Wave front tilt of radiation that is backscattered from the retina is calculated as a best fit from the set of projections. The axis of best vision or the visual axis is reconstructed from a set of those traces of chief rays exiting from the eye that cross the nodal point of the optical system of the eye and that are normal to the wave front tilts. Measuring with the Styles Crawford scans centered over this axis provides the most accurate objective refraction.