Abstract
Purpose :
Disability glare is a consequence of straylight that causes discomfort and an objective perceptual deficit. The novel computer-based AIM Glare Acuity method was used to measure subjective and objective performance under standard and simulated straylight conditions.
Methods :
AIM Acuity(Figure 1) entailed a sequence of 2 trials, each containing a 4*4 grid of 6° cells displayed on a 32” 4K monitor, using a gray background(3.4 cd/m2). Each cell contained a dark Landolt-type C surrounded by either a 0.1° thin dark(0.2 cd/m2; Baseline), 1° thick dark(Mask control), or 1° thick light(195 cd/m2; Glare) ring. Each C was randomly rotated and varied in size, spanning easy to difficult sizes. An adaptive algorithm updated the sizes in the 2nd trial based on the participant’s responses during trial 1. Participants indicated the location of each C’s gap via mouse click on the surrounding ring. The angle between the true and reported C orientation as a function of stimulus size that was fit with a cumulative gaussian function, from which ETDRS-equivalent acuity was also calculated(Figure 1). After each trial, participants indicated their subjective glare experience via continuous sliders, ranging from “No glare” to “Strong glare”. After 5 min dark adaptation, 18 normally-sighted participants(18 years median age) performed the task using their dominant eye without(control) or with a Bangerter 0.3 filter(simulated straylight condition) at 60cm distance. ANOVAs and planned comparisons determined effects between conditions.
Results :
AIM Glare Acuity took 39sec(SD=17sec) to complete. Visual acuity was significantly lower with Glare rings for both control and simulated straylight conditions, but with a much stronger effect for the latter(Figure 2). No significant differences were found between Baseline and Mask dark rings for any condition. Subjective experiences of glare were significantly higher in glare than control ring conditions.
Conclusions :
Visual acuity and subjective discomfort reports were significantly impaired by AIM Glare rings and the effects were amplified by stimulated straylight. Dark mask control rings did not affect acuity or discomfort, suggesting that performance was impaired by disability glare rather than contrast masking. AIM Glare Acuity may therefore be suitable to investigate disability glare in <40 sec in clinical populations, e.g. patients pre-/post- refractive or cataract surgery.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.