Yaw Buabeng¹ (), Billy Hammond¹, Lisa Renzi-Hammond¹; ¹University of Georgia

Intraocular light scatter significantly impairs visual performance and is a critical factor in limiting the ability to perform vision-dependent tasks, such as safe driving. Visual stimuli—ranging from lighting and road signs to lenses and ocular implants—can be optimized to minimize the detrimental effects of scatter. The success of such optimizations relies on accurate data concerning the behavioral effect of light spread across different wavelengths within the eye. This study aims to provide foundational data to inform and enhance the design of visual aids and stimuli for improved visual performance. Light spread was measured using two small light points (2 mm apertures in a light shield with a collapsible baffle) back lit with homogeneous monochromatic light (a 1000-W Xenon source used in conjunction with narrow-band interference filters). These points were perceived as one point of light when adjacent. Two-point thresholds were defined as the minimum separation necessary to perceive two non-overlapping points. Subjects sat approximately 67 mm away from the source. Eye position was stabilized using an adjustable chin-and-forehead rest assembly (alignment with the optic axis was done using a small aperture near the plane of the eye physically aligned with the stimulus). 60 young healthy subjects with good acuity were tested. The wavelengths were equated for energy in order to isolate the effects of wavelength (i.e., an action spectrum). The results indicated that the shortest wavelengths required the largest separation (p<0.001) with a general monotonic decrease as the wavelength increased (plateauing around 580 nm). These data indicate a strong effect of wavelength on the perception of intraocular scattered light.