| Popis: |
The effects on visual performance of colored filters were investigated. Visual performance of 10 subjects (mean age = 30.5) was assessed while wearing yellow and pink tinted filters and compared to performance with transmission matched neutral filters and without any filter. Visual acuity was assessed with high (96%) and low (11%) contrast letter charts at mean luminance of 100 and 3 cd/m2. Contrast sensitivity for blue/grey and green/grey gratings was assessed at 5 spatial frequencies (0.45, 0.9, 3, 6, 12cpd) at grating mean luminance of 36 cd/m2. Visual search performance for grey targets on blue and green backgrounds viewed with and without the yellow and pink filters respectively, was assessed at moderate and low photo-optic ambient levels. Both the pink and yellow filters reduced contrast acuity compared to the no filter condition at 3 cd/m2, but had no effect on acuity at 100 cd/m2. Sensitivity to color contrast at mid spatial frequencies was improved with the pink filter, although the yellow filter did not change sensitivity at any frequency. Furthermore, both the pink and yellow filters improved search times at the moderate ambient level, and the pink filter improved search times at the low ambient level. Tinted filters can improve visual performance in situations where they significantly increase the luminance and or color contrast differences between targets and backgrounds. |
