Characterization and operation of a liquid crystal adaptive optics phoropter

Abstract

Adaptive optics (AO), a mature technology developed for astronomy to compensate for the effects of atmospheric turbulence, can also be used to correct the aberrations of the eye. The classic phoropter is used by ophthalmologists and optometrists to estimate and correct the lower-order aberrations of the eye, defocus and astigmatism, in order to derive a vision correction prescription for their patients. An adaptive optics phoropter measures and corrects the aberrations in the human eye using adaptive optics techniques, which are capable of dealing with both the standard low-order aberrations and higherorder aberrations, including coma and spherical aberration. High-order aberrations have been shown to degrade visual performance for clinical subjects in initial investigations. An adaptive optics phoropter has been designed and constructed based on a Shack-Hartmann sensor to measure the aberrations of the eye, and a liquid crystal spatial light modulator to compensate for them. This system should produce near diffraction-limited optical image quality at the retina, which will enable investigation of the psychophysical limits of human vision. This paper describes the characterization and operation of the AO phoropter with results from human subject testing.

Eye Vision Testing System and Eyewear Using Micromachines

“…In 1996, an LC diffractive-optic E-Lens had been designed [29] and in 2006, the Peyghambarian group suggested the use of the LC diffractive-optic E-Lens for eye exams to measure eye refractive power change [30]. In 2003, a team from Lawrence Livermore National Lab demonstrated an adaptive optics phoropter where a Shack-Hartmann sensor was used to measure the aberrations of the eye and an LC SLM was used to compensate these eye aberrations [31].…”

Liquid Crystal Wavefront Correctors

“…In recent years, Prof. Xuan's group has completed series of valuable studies [31][32][33][34][35][36][37][38][39][40][41][42]. Recently, the applications of LCWFC have been extended to other fields, such as retina imaging [43][44][45], beam control [46][47][48][49][50], optical testing [41], optical tweezers [51][52][53], dynamic optical diffraction elements [54][55][56][57], tuneable photonic crystal fibre [58,59], turbulence simulation [60,61] and free space optical communications [62,63].…”

Impact of Liquid Crystals in Active and Adaptive Optics

“…The active and adaptive optics philosophy has been applied in different fields of research. Clinical applications for early diagnosis and patient monitoring as well as basic studies on physiological optics and vision science have also benefited in the last few years [ 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 ]. Low price, easy handling and easy control of LCSLMs are the main reasons that have encouraged different research groups to initiate lines of research based on SLMs that were initially restricted to well funded groups capable of acquiring the expensive deformable mirrors.…”