Optical Visual Quality Analysis Based on Double-Pass Technology

Abstract

The double-pass technique used in ophthalmology for the measurement of point spread function was first proposed by Flamant in 1956 [1]. The design principle is after several reflections, the point light source is imaged on the retina after passing through the refractive medium, the retina image is then reflected, and the light is returned through the original path where the acquisition system collects and analyzes the double-pass light to obtain the light energy distribution of the retinal imaging. Subsequently, in 1994, Westheimer et al. [2] proposed a way to analyze the light energy distribution of double-pass images to investigate the combined effects of aberrations and intraocular scatter on retinal image quality. The current available optical visual quality analysis system (OQAS II) based on the double-pass principle design is produced in Spain. The schematic diagram is shown in Fig. 2.1. The point light source passing through the refractive medium of the human eye to reach the retina is the first pass and together with the light that is reflected from the retina and collected forms the double-pass system. By analyzing the imaging shape and light energy distribution of the point light source on the retina, the combined effect of ocular aberrations and intraocular scatter on the optical quality of the human eye can be obtained.