Characterising Eye-Related Optical Systems

Abstract

An instrument and method for characterising eye-related optical systems, including the live human eye ( 18 ) involves scanning an illuminating light beam ( 22 ) from a light source and light detector unit ( 20 ) from element to element of a beam deflector array ( 12 ) of elements ( 14 ) arranged laterally across the optical axis ( 16 ) of eye ( 18 ). At each successive element ( 14 ) the illuminating beam ( 22 ) is deflected to form an interrogating beam ( 24 ) that is directed into the eye ( 18 ) at a peripheral angle that depends upon the lateral location of the deflector element. A return beam ( 23 ) is reflected or back-scattered from the cornea ( 38 ) and returned via the same deflector element to the light source and detector unit ( 20 ). This allows the interrogating beams to be scanned sufficiently rapidly into the eye to greatly reduce the variation of eye fixation and gaze that accompany other methods of measuring peripheral refraction or aberration of a natural eye. In addition to or instead of scanning the illumination beam ( 22 ) over each element ( 14 ) of the array ( 12 ), all or multiple elements ( 14 ) of the array ( 12 ) can be illuminated simultaneously and the multiple interrogating rays ( 24 ) thus generated can be gated by the use of an LCD aperture plate ( 26 ). Alternatively, an LCD aperture plate ( 28 ) can be interposed between a wide illuminating beam ( 22 ) and operated to selectively illuminate the beam deflector.

1 . A method of optically characterising an eye-related optical system having a longitudinal optical axis, the method including the steps of:
 generating an interrogating light beam from each element of an array of discrete beam deflector elements, which array that extends laterally from the optical axis,   directing said light beam into the eye-related system at an angle relative to the optical axis which is at least in part determined by the lateral position of the element within said array,   detecting a return beam from the eye-related system that is generated by said interrogating light beam and that is returned at said angle via said beam deflector element to detector means, and   comparing said detected returned beam with said interrogating beam or an image of to determine aberrations of the eye-related optical system at said angle.   
     
     
         2 - 21 . (canceled)