Apparatus and method for determining objective refraction using wavefront sensing

Abstract

An apparatus for determining the objective refraction of a patient's eye includes a transparent window and a wavefront measurement device that determines aberrations in a return beam from the patient's eye after the beam passes through a corrective test lens in the apparatus. The wavefront measurement device outputs an instant display representative of the quality of vision afforded the patient through the test lens. The display can be a representation of a Snellen chart, convoluted with the optical characteristics of the patient's vision, an overall quality of vision scale or the optical contrast function, all based on the wavefront measurements of the patient's eye. The examiner may use the display information to conduct a refraction examination and other vision tests without the subjective response from the patient.

1 . A method for indicating the quality of a patient's vision, comprising: providing a phoropter through which a patient can look at a target spaced from the phoropter; directing a laser beam into an eye of a patient when the patient looks into the phoropter; detecting aberrations in a wavefront of the light beam as the light beam returns from the patient's eye; and at least partially based on the detecting act, indicating a quality of a patient's vision. 
   
   
       2 . The method of  claim 1 , further comprising associating at least one test lens with the phoropter, positioning the test lens in the patient's line of sight, the wavefront being detected after the laser beam returning from a patient's eye passes through the test lens. 
   
   
       3 . The method of  claim 1 , wherein the act of indicating includes generating an image of the target at least partially based on the wavefront. 
   
   
       4 . The method of  claim 1 , wherein the act of indicating includes generating at least one visual display representative of an effectiveness of the lens in correcting the patient's vision. 
   
   
       5 . The method of  claim 4 , wherein the visual display comprises at least one from the list: (1) an image generated by a convolution of the image of the target based on the wavefront returning from the patients eye and through the test lens; (2) a numerical and/or graphic display representative of the effectiveness of the test lens; (3) a numerical and/or graphic display of the contrast function of the patient's vision. 
   
   
       6 . The method of  claim 4 , wherein the visual display includes at least one color-coded display. 
   
   
       7 . The method of  claim 5 , further comprising determining the refraction for the patient. 
   
   
       8 . The method of  claim 7 , further comprising: evaluating the display representing the effectiveness of the lens; selecting a second test lens set from the lenses; positioning said second test lens in the patient's light of sight; and generating at least a second visual display representative of an effectiveness of the second test lens in correcting a patient's vision. 
   
   
       9 . The method of  claim 8 , wherein said visual display is generated substantially instantaneously following positioning of the second test lens in the patient's line of sight. 
   
   
       10 . The method of  claim 7 , wherein the determining further comprises prescribing ophthalmic lenses for the patient. 
   
   
       11 . The method of  claim 10 , wherein prescribing further comprises dispensing ophthalmic lenses for correcting the refractive errors of the patient based on either (i) the low order aberrations including the sphere, cylinder and axis, or (ii) low order aberrations in (i) and the higher order aberrations including the third order and higher Zernike terms. 
   
   
       12 . The method of  claim 8 , wherein the selecting of a second test lens comprises determining at least one of the following: (a) the onset of the patient's accommodation, and (b) the range of the patient's accommodation. 
   
   
       13 . The method of  claim 8 , wherein the selecting of a more suitable trail lens comprises “fogging” the patient.