acquired color deficiency in the tritan axis in parkinson’s disease has already been reported, manifesting itself as impaired performance in various visual tasks. however, its clinical significance has always been controversial. in this study we evaluated the performance of parkinson s disease patients in lanthony 15-desaturated clinical test and for the first time, compared it with the standar...

Two experiments explore the color perception of objects in complex scenes. The first experiment examines the color perception of objects across variation in surface gloss. Observers adjusted the color appearance of a matte sphere to match that of a test sphere. Across conditions we varied the body color and glossiness of the test sphere. The data indicate that observers do not simply match the ...

Many recent computational models of surface color perception presuppose information about illumination in scenes. The models differ primarily in the physical process each makes use of as a cue to the illuminant. We evaluated whether the human visual system makes use of any of three of the following candidate illuminant cues: (1) specular highlight, (2) full surface specularity [Lee, H. C. (1986...

background. the color masking ability of a restoration plays a significant role in coveringa discolored substructure; how-ever, this optical property of zirconia ceramics has not been clearly determined yet. the aim of this in vitro study was to evaluate the color masking ability of a zirconia ceramic on substrates with different values. methods. ten zirconia disk specimens,0.5 mm in thickness ...

1.4 The ultra-violet, the infra-red, and the spectral sensitivity of the eye 16 1.5 Color constancy, color contrast, and color harmony 19 1.6 Color deficiency 22 1.6.1 Inherited color deficiency 22 1.6.2 Acquired deficiencies of color perception 25 1.7 The golden age (1850–1931) 26 1.7.1 Color mixture 26 1.7.2 The spectral sensitivities of the receptors 29 1.7.3 Anomalous trichromacy 31 1.7.4 T...

Traditional trichromatic theories of color vision conclude that color perception is not possible under scotopic illumination in which only one type of photoreceptor, rods, is active. The current study demonstrates the existence of scotopic color perception and indicates that perceived hue is influenced by spatial context and top-down processes of color perception. Experiment 1 required observer...

The importance of including an adequate test for the discovery of deficiencies in color vision in any thorough medical examination of students has long been recognized; it is obviously desirable to detect at an early age those individuals who will be excluded from pursuing careers in occupations which require good color perception. For several years the Ishihara color vision test was used as pa...

objectives: masking ability of a restorative material plays a role in hiding colored substructures; however, the masking ability of zirconia ceramic (zrc) has not yet been clearly understood in zirconia-based restorations. this study evaluated the effect of three different core materials on masking ability of a zrc. materials and methods: ten zirconia disc samples, 0.5mm in thickness and 10mm i...