A handheld adaptive optics device for personalized visual evaluation

Abstract

Visual simulation is an emerging technology used in ophthalmology where a subject sees through manipulated optical conditions. The existing visual simulation tools are quite advanced and trailblazing. However, they cannot follow the miniaturization and mobility trends of the technology. Current visual simulators are bulky in size and require a tabletop arrangement for operation. Here we propose a novel handheld and portable adaptive optics visual simulator that can induce a variety of optical corrections and measure ocular aberrations in real-time while realizing the form-factor similar to the typical virtual reality headsets. The proposed device has two main parts: a wavefront shaping module for manipulation of visual stimuli and a wavefront sensing module for evaluation of ocular aberrations, which are integrated into a standalone handheld unit. The device incorporates a micro-display and a liquid crystal-on silicon (LCOS) phase modulator for wavefront shaping combined with a Hartmann-Shack (HS) wavefront sensor. Our prototype device incorporates miniature optical components and a path folding mechanism combined with in-house 3D printed mounts and covers to reduce the device footprints. The prototype device is tested by inducing the known values of defocus and astigmatism through a set of trial lenses, measuring the induced aberrations, and evaluating the simulated corrections. Our results show high measurement accuracy (R²>0.999) when tested on spherical and cylindrical trial lenses ranging from -10 to 10 diopters and -5 to 5 diopters, respectively. The visual correction performance shows better than 20/20 visual acuity resolution for the defocus correction of -5 to 5 diopters.