CORRECTION OF THE ABERRATIONS IN THE HUMAN EYE WITH A LIQUID-CRYSTAL SPATIAL LIGHT-MODULATOR - LIMITS TO PERFORMANCE

We evaluated the performance of a liquid-crystal spatial light modulat or for static correction of the aberrations in the human eye. By apply ing phase-retrieval techniques to pairs of double-pass images we first estimated the wave aberration of the eye to be corrected. Then we int roduced the opposite phase map in the modulator, which was placed in a plane conjugated with the eye's pupil, and we recorded double-pass im ages of a point source before and after correction of the aberrations. In a slightly aberrated artificial eye a clear improvement was obtain ed after correction, and, although diffraction-limited performance was not achieved, the results were close to the theoretical predictions. In the two living eyes that we studied some benefit also appeared in t he correction, but the performance was worse than that expected. We ev aluated possible explanations for the relatively poor performance that was obtained in the human eye: an incorrect estimate of the ocular ab erration, the limited spatial resolution of the modulator, and the dyn amic changes in the ocular aberrations. Based on the results in the ar tificial eye, the first problem was not considered to be a major sourc e of error. However, we showed that the spatial resolution of the liqu id-crystal spatial light modulator limits the maximum correction to be attained. In addition, the changes in the ocular optics over time als o impose a limit in the performance of static corrections. (C) 1998 Op tical Society of America.