Application of Blue Filters Increases the Usefulness of Moreland Test in Anomaloscopic Color Vision Assessment for Blue–Green Color Range

Abstract

The effect of blue light filters on the anomaloscopic examination was analyzed. Thirty subjects (18–43 y, 20 female, 10 male) without color vision disorders were examined in 4 filter conditions: no filter (F-0), Blue Control Hoya (F-BC), Med-1 JZO (F-Med1) and 450 Eschenbach (F-450). Both Rayleigh test (red–green axis) and Moreland test (blue–green axis) were performed. Application of F-BC filter shows negligible effect on color vision perception in both tests. Contrary to this, the application of strong F-450 filter causes significant shift in Moreland test towards tritanopy and the decrease in correlations of Moreland parameters with Rayleigh test parameters. The application of medium strong F-Med1 filter causes the slight shift in Moreland test towards the center of the Moreland scale and increases the Spearman correlations between Moreland and Rayleigh test parameters. This observation suggests that the about 15–40% reduction of blue diode intensity in the Moreland test may be beneficial in detecting mild changes in color vision perception in the blue-green axis and may improve its usefulness in evaluating the color vision perception disorders accompanying different illnesses, such as diabetes, glaucoma, neuritis optica, or cataract. The discussion concerning the modifications of Moreland test construction is also presented.

Color vision assessment following cataract surgery using anomaloscope

“…The following set of four parameters was analyzed from the data obtained in both the Rayleigh and the Moreland tests: R 1 -the lower limit of the matching range for the Rayleigh test, R 2 -the upper limit of the matching range for the Rayleigh test, R C = (R 1 +R 2 ) / 2 -central matching for the Rayleigh test, R W = R 2 -R 1 -the width of the matching range for the Rayleigh test, M 1 -the lower limit of the matching range for the Moreland test, M 2 -the upper limit of the matching range for the Moreland test, M C = (M 1 + M 2 ) / 2 -central matching for the Moreland test, M W = M 2 -M 1 -the width of the matching range for the Moreland test. As discussed in our previous studies [26,27], the decrease in R 1 corresponds mainly to the deterioration in green color visibility, while the increase in R 2 mainly corresponds to the deterioration in red color visibility. Similarly, the decrease in M 1 corresponds mainly to poorer blue color visibility and the increase in M 2 to inferior green visibility.…”

“…Similarly, in the Moreland test, the light emitted by the blue (430 nm) and green (490 nm) diodes is mixed and the resulting hue is compared against the reference cyan diode (480 nm). As shown in our previous studies [26,27], the device is sensitive mainly to deficits in the red-green axis (the Rayleigh test, Oculus anomaloscope). Color vision changes in the blue-green axis are much harder to detect using the Moreland test provided by the Oculus anomaloscope [27].…”

“…As shown in our previous studies [26,27], the device is sensitive mainly to deficits in the red-green axis (the Rayleigh test, Oculus anomaloscope). Color vision changes in the blue-green axis are much harder to detect using the Moreland test provided by the Oculus anomaloscope [27]. As the crystalline lens begins to lose translucency with age, absorption of short-wave visible light increases, leading to tritanopia-like deficits [28,29].…”

“…Color vision test was administered in a dim room using the HMC Anomaloskop MR47700 (Oculus). The test protocol was in accordance with the device user's manual [31] and the same as described in our previous papers [26,27]. Prior to the test, the subjects adapted to the light conditions for 10 minutes.…”

“…The HMC Anomaloskop MR47700 includes two tests i.e. the Rayleigh test, which has been commonly adopted and measures the sensitivity to red and green colors, and the Moreland test, which measures the relation between the blue and green color sensitivity [26,27]. The idea of the Rayleigh test is based on finding the proportion of red (666 nm) and green light (549 nm) intensity that results in a hue impression identical to the yellow reference diode (589 nm).…”