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Color blindness occurs when the person is unable to see colors in a normal way. It is also known as colour deficiency. In Trichromacy, three types of cones are present and working properly. Patient can see all colors on the visible spectrum of light in the traditional way. This is full colour vision. In Anomalous trichromacy. There are three types of cones, but one type isn’t as sensitive to light in its wavelength as it should be. As a result, person doesn’t see colors in the traditional way, with variations from normal ranging from mild to severe. In Dichromacy, one type of cone is missing. So, only two types of cones (usually S cones along with either L cones or M cones) are present. In Monochromacy: Person has only one type of cone or no cone function at all, so very limited or no ability to see color. There are four main subtypes: a.Protanopia: In this condition, in the person L cones are missing. So, person can’t perceive red light. Mostly see colors as shades of blue or gold. b.Deuteranopia: In this condition, in the person M cones are missing. So, person can’t perceive green light. Mostly see blues and golds. c.Protanomaly: In this condition, the person has all three cone types, but L cones are less sensitive to red light than they should be. Red may appear as dark gray, and every color that contains red may be less bright. d.Deuteranomaly: In this condition, the person has all three cone types, but M cones are less sensitive to green light than they should be. Mostly see blues, yellows and generally muted colours. The colour blindness can be diagnosed by the Ishihara test, Colour vision test. Colour vision tests and Genetic testing.


Colour Vision Trichromacy Monochromacy Ishihara Test Genetic Testing Cones

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Vinjavarapu L.Anusha, Raeefa Mirza, Mohammed Salmon, Shaik Wahajuddin, Zoha Shaik, Mohammed Abdul Bari Ahmed, & G. Sudhakara rao. (2023). Pathophysiology and pharmacological study of colour blindness. International Journal of Research in Pharmacology & Pharmacotherapeutics, 12(3), 210-214.


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