Abstract
Spectrally-selective luminance filters (SSLFs) can be designed to enhance color perception by creating greater separation between medium and long wavelengths. Whether SSLFs normalize color contrast sensitivity (CCS) for red and green stimuli in inherited red-green color deficient (CD) observers is unknown. We assessed change in CCS for red and for green stimuli in 80 healthy adult eyes (69 color normal, CN; 11 CD). Using a clinical instrument (ColorDx, Konan Medical), subjects identified the gap in an isoluminant Landolt C via a 4-alternative forced choice procedure. The psi-marginal adaptive method was used to determine CCS threshold. Eight blocks were used to test 2 stimulus sizes, 2 colors, and 2 filter conditions, all constant within a block and viewed at 60 cm. The mean change in CCS from no filter to SSLF condition was significantly different for CN compared to CD observers (Red, logMAR =1.04:p < .001; Green, logMAR = 1.04: p = .008). Multiple linear regression of change in CCS on age, gender, visual acuity, color vision status, history and number of mild traumatic brain injuries was significant only for color vision status for both colors (p < .001). For logMAR = 1.22 size stimuli, the distributions of change in CCS were significantly different for CN vs CD observers (red: p < .0001; green: p = .018). Comparison of CCS without filter for CN and CCS with filter for CD showed no significant difference in the distributions for the logMAR = 1.04 stimuli (p = 0.12) nor for the logMAR = 1.22 red stimulus (p = 0.08), but a significant difference emerged for CN vs CD observers for the logMAR = 1.22 green stimulus (p = 0.04). Change in CCS produced by SSLFs normalizes CCS for CD observers. Whether CCS can predict subjective success with SSLFs remains to be explored.