Protanopia is a deficiency in colour vision in which those affected are insensitive to red light and confuse red, yellow, and green colours. Protanopia may therefore be classed as a form of colour blindness.
Protanopia is one of three forms of dichromacy, whose adjective is dichromatic.
People with dichromacy are called dichromats, which means that they can match any colour with some mixture of just two (2) wavelengths of light, whereas normally-sighted people are 'trichromats', meaning that they need three (3) wavelengths of light in order to acceptably match any colour of light.
Protanopia affects far more males than females. It also involves a darkening of the red end of the spectrum to such an extent that red colours may appear to be black.
For comparison (in short summary):
- Protanopia - involves inability to distinguish between colours in the green-yellow-red section of the spectrum due to lack of the long-wavelength sensitive retinal cones.
- Deuteranopia - involves inability to distinguish between colours in the green-yellow-red section of the spectrum due to lack of the medium-wavelength sensitive retinal cones.
- Tritanopia - involves inability to distinguish between the colours in the blue-yellow section of the spectrum.
See also more general information about colour blindness.
More about Ophthalmology:
This section includes short definitions
of many diseases, disorders, and conditions of the eyes and visual system.
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- A diagram of the eye
- Definitions and descriptions of the parts of the eye
- A concise description of the human retina
- Definitions of parts of the retina
- Clinical and surgical procedures re. eyes and human visual system
For further information see also our pages of books about ophthalmology.