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Size effect of color patches for their color appearance with foggy goggles simulating cloudy crystalline lens of elderly people
Author(s) -
Ikeda Mitsuo,
Pungrassamee Pontawee,
Obama Tomoko
Publication year - 2009
Publication title -
color research and application
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 62
eISSN - 1520-6378
pISSN - 0361-2317
DOI - 10.1002/col.20503
Subject(s) - brightness , luminance , illuminance , optics , lightness , color vision , contrast (vision) , computer vision , color discrimination , lens (geology) , perception , computer science , optometry , artificial intelligence , psychology , physics , medicine , neuroscience
The cataract eyes can be characterized by three elements; luminance, spectral distribution, and scatter, which are perceived as brightness, color, and fogginess, respectively. Change of any of the three elements may affect visual performance. The foggy element, which refers to the perception associated with a change in the optical scatter of the crystalline lens, causes deterioration of the visual acuity, pattern perception, and an uncomfortable foggy appearance over the visual field. Moreover, it also affects the ability to discriminate and perceive colors. The environmental light coming to the eyes from all directions overlay the retinal image of a color patch and causes to reduce the color purity of the image. Color desaturation of the patch takes place. In this article, it is suggested that if the patch is enlarged in size the environmental light coming from the immediate surroundings of the patch is replaced by the color of the patch itself reducing the desaturation of the patch and leading to a greater perception of the original patch color. Three foggy filters were made to fit goggles and subjects, while wearing the goggles, were allowed to observe red, yellow, green, and blue color patches of six different sizes under four different illuminance levels to control the strength of the environmental light. When the color patch size was small as 0.7° of visual angle the chromaticness perceived on each of the color patches was extremely small under an environmental light of 300 lx, but increased rapidly as the color patch size increased to 5.9° of visual angle. When the environmental light was reduced to 10 lx, the degree of apparent color desaturation was markedly reduced to only a slight amount. The haze value of the foggy filters was also found to be significant with the larger the haze value the stronger the desaturation of the test color patches. © 2009 Wiley Periodicals, Inc. Col Res Appl, 34, 351–358, 2009