Effect of digitally generated colored filters on Farnsworth-Munsell 100 hue test by red-green color vision-deficient observers

2021 ◽  
Vol 2021 (29) ◽  
pp. 148-153
Author(s):  
Shunnma Saito ◽  
Keiko Sato

In this study, the effects of four different digitally generated colored filters on the Farnsworth-Munsell 100 hue test (100-hue test) are analyzed by red-green color-vision deficient (CVD) observers. We digitally simulate the colored filters based on the spectral transmittance of four colored filters, which have been used previously. Five red-green CVD observers are subjected to the 100-hue test on a monitor under nine filter conditions, which comprise one condition without filter and eight conditions with filters. The results suggest that a colored filter that transmits long wavelengths and absorbs medium wavelengths may improve the color discrimination performance of protans and deutans.

2019 ◽  
Vol 36 ◽  
Author(s):  
Keiko Sato ◽  
Takaaki Inoue ◽  
Shuto Tamura ◽  
Hironori Takimoto

AbstractPrevious studies have shown that with the use of tinted lenses (or colored filters), individuals with red–green color vision deficiency (CVD) report an improvement in their performance on certain color vision tests. In this context, this study examines the effects of a digitally generated red-colored filter and identifies the mechanism mainly responsible for the changes in red–green CVD observers’ performance on a D-15 arrangement test performed using the filter. We simulate the red filter digitally with the spectral transmittance similar to that of the X-Chrom, which is a red-tinted lens. Fourteen red–green CVD subjects are subjected to the D-15 test on a computer monitor under four filter conditions, consisting of one condition without the filter and three conditions with the filter, corresponding to the opacity of the red filter. The results show that while the simulated red filter improves the performance of deutans to arrange the caps in the D-15 test, this is not the case for protans. In addition, considerations based on the human cone-contrast model enable us to identify that the improvement in deutan observers largely results from the increase in the luminance contrast between stimuli and a background. To summarize, the red filter simulated in this study induces different changes in the red–green CVD observer luminance contrast between the protan and deutan types, with the result that the performance of deuteranopes improves while that of protanopes deteriorates.


2021 ◽  
Vol 224 (12) ◽  
Author(s):  
Matthew B. Toomey ◽  
Kelly L. Ronald

ABSTRACT Carotenoids color many of the red, orange and yellow ornaments of birds and also shape avian vision. The carotenoid-pigmented oil droplets in cone photoreceptors filter incoming light and are predicted to aid in color discrimination. Carotenoid use in both avian coloration and color vision raises an intriguing question: is the evolution of visual signals and signal perception linked through these pigments? Here, we explore the genetic, physiological and functional connections between these traits. Carotenoid color and droplet pigmentation share common mechanisms of metabolic conversion and are both affected by diet and immune system challenges. Yet, the time scale and magnitude of these effects differ greatly between plumage and the visual system. Recent observations suggest a link between retinal carotenoid levels and color discrimination performance, but the mechanisms underlying these associations remain unclear. Therefore, we performed a modeling exercise to ask whether and how changes in droplet carotenoid content could alter the perception of carotenoid-based plumage. This exercise revealed that changing oil droplet carotenoid concentration does not substantially affect the discrimination of carotenoid-based colors, but might change how reliably a receiver can predict the carotenoid content of an ornament. These findings suggest that, if present, a carotenoid link between signal and perception is subtle. Deconstructing this relationship will require a deeper understanding of avian visual perception and the mechanisms of color production. We highlight several areas where we see opportunities to gain new insights, including comparative genomic studies of shared mechanisms of carotenoid processing and alternative approaches to investigating color vision.


Genetics ◽  
2001 ◽  
Vol 158 (4) ◽  
pp. 1697-1710 ◽  
Author(s):  
Shozo Yokoyama ◽  
F Bernhard Radlwimmer

Abstract To better understand the evolution of red-green color vision in vertebrates, we inferred the amino acid sequences of the ancestral pigments of 11 selected visual pigments: the LWS pigments of cave fish (Astyanax fasciatus), frog (Xenopus laevis), chicken (Gallus gallus), chameleon (Anolis carolinensis), goat (Capra hircus), and human (Homo sapiens); and the MWS pigments of cave fish, gecko (Gekko gekko), mouse (Mus musculus), squirrel (Sciurus carolinensis), and human. We constructed these ancestral pigments by introducing the necessary mutations into contemporary pigments and evaluated their absorption spectra using an in vitro assay. The results show that the common ancestor of vertebrates and most other ancestors had LWS pigments. Multiple regression analyses of ancestral and contemporary MWS and LWS pigments show that single mutations S180A, H197Y, Y277F, T285A, A308S, and double mutations S180A/H197Y shift the λmax of the pigments by −7, −28, −8, −15, −27, and 11 nm, respectively. It is most likely that this “five-sites” rule is the molecular basis of spectral tuning in the MWS and LWS pigments during vertebrate evolution.


Science ◽  
1965 ◽  
Vol 149 (3688) ◽  
pp. 1113-1114 ◽  
Author(s):  
C. A. Boneau ◽  
M. K. Holland ◽  
W. M. Baker

2016 ◽  
Vol 57 (8) ◽  
pp. 3853 ◽  
Author(s):  
Emily J. Patterson ◽  
Melissa Wilk ◽  
Christopher S. Langlo ◽  
Melissa Kasilian ◽  
Michael Ring ◽  
...  

2010 ◽  
Vol 28 (1) ◽  
pp. 51-60 ◽  
Author(s):  
CHRISTIAN PULLER ◽  
SILKE HAVERKAMP

AbstractColor vision in mammals is based on the expression of at least two cone opsins that are sensitive to different wavelengths of light. Furthermore, retinal pathways conveying color-opponent signals are required for color discrimination. Most of the primates are trichromats, and “color-coded channels” of their retinas are unveiled to a large extent. In contrast, knowledge of cone-selective pathways in nonprimate dichromats is only slowly emerging, although retinas of dichromats like mice or rats are extensively studied as model systems for retinal information processing. Here, we review recent progress of research on color-coded pathways in nonprimate dichromats to identify differences or similarities between di- and trichromatic mammals. In addition, we applied immunohistochemical methods and confocal microscopy to retinas of different species and present data on their neuronal properties, which are expected to contribute to color vision. Basic neuronal features such as the “blue cone bipolar cell” exist in every species investigated so far. Moreover, there is increasing evidence for chromatic OFF channels in dichromats and retinal ganglion cells that relay color-opponent signals to the brain. In conclusion, di- and trichromats share similar retinal pathways for color transmission and processing.


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