The three variables of color vision are hue, saturat ion, and brightness. The characterist ic color differences along the spectrum which the color-normal sees are essentially concerned with hue. In measurements of wavelength discrimination the precise value of the just perceptible difference in wavelength at constant brightness is no doubt influenced by saturat ion differences, bu t the major f...

Techniques that involve the use of comb-filtered spectra to study human colour vision have been developed in previous work (Bonnardel, V., Bellemare, H., Mollon, J.D., 1996. Measurements of human sensitivity to comb-filtered spectra, Vision Research 36, 2713-2720; Bonnardel, V., Ruderman D.L., Barlow, H.B., 1997. A fast determination of the Spectral Modulation Sensitivity Function: a comparison...

Congenital colour vision defects affect about 8% and 0.5% of the male and female population, respectively. Pseudoisochromatic Ishihara plates have shown to be successful in an early diagnosis of colour vision defects. This commonly used colour vision test was initially intended to identify those who suffered from red-green aspect of congenital colour blindness; however, it may be of use to reve...

Along with subterranean maps, the new site will also include environmental data that will help users gather more data on climate change. “In discussions about climate change, the world’s oceans are often overlooked despite being an integral part of the issue. About one third of the carbon dioxide that we emit into the atmosphere ends up in the oceans,” says Schmidt. It was no coincidence that A...

Two complementary studies have resolved the circuitry underlying green-blue color discrimination in the retina. A blue-sensitive interneuron provides the inhibitory signal required for computing green-blue color opponency.

Decreased discrimination of colors caused by adverse environment, such as long-term occupational exposure to or consumption of drugs, substances, and food containing neurotoxic chemicals. Color vision early manifests adverse effects of exposure to an environment that contains neurotoxic substances [1, 2]. The acquired color vision impairments, or dyschromatopsias, can be very subtle (subclinica...

The term“tetrachromacy” describes the physiological possession of four different classes of simultaneously functioning retinal photopigments (also called “weak tetrachromacy”). From an empirical standpoint, tetrachromatic color vision (or “strong tetrachromacy”) additionally requires demonstrating that mixtures of four independent appropriately chosen primary lights will simulate all distinctio...

Revision date: 03-01-2005 Newton, Young, Maxwell, and Schrodinger were all central figures in the history of color science [20]. This chapter brings up to date a previous version written by the color scientist Edwin Land, who was himself renowned as an inventor and founder of the Polaroid Corporation, but who maintained an active interest in the psychology of human color vision throughout his c...

Both acquired color vision deficiencies and abnormal pattern electroretinograms (PERGs) are observed in patients with ocular hypertension (OHT) as well as in patients with glaucoma. In the present study we determined the prevalence of both of these functional deficits in a large group of OHT patients (N = 130). Color vision was tested with the desaturated D-15 and a color confusion score was us...