Influence of yellow filters on straylight measurements.

PURPOSE: To determine whether the yellow filters often used for glare reduction influence retinal straylight measured in healthy eyes.

SETTING: Department of Ophthalmology, Antwerp University Hospital, Edegem, Belgium.

DESIGN: Prospective case series.

METHODS: For each eye, the spherical equivalent (SE) was determined using an autorefractometer, followed by 5 straylight measurements taken with the compensation-comparison method. The first measurement was taken with a colorless plano lens placed in front of the eye, followed by 4 other measurements with yellow filters with cutoff wavelengths at 450 nm, 511 nm, 527 nm, and 550 nm. Ametropic volunteers were corrected using an additional lens in all measurements. Age, sex, and eye color were listed. In addition to the basic measurements, base- and age-corrected and base-, age-, and SE-corrected values were calculated.

RESULTS: The data from 56 right eyes of 56 healthy volunteers aged 28.7 years ± 10.3 (SD) were assessed. The straylight of the 4 yellow filters was significantly higher than that of the plano lens (P < .001, analysis of variance [ANOVA]). The straylight also increased with higher cutoff frequencies, albeit insignificantly (P > .05, ANOVA). No significant difference was found between sexes (P = .909) or between eye colors (P > .05).

CONCLUSIONS: The use of yellow filters increased retinal straylight by a small but significant amount compared with the use of unfiltered light. This suggests that the visual comfort often experienced while wearing these filters is not associated with reduced straylight.