Normal Colour Vision

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Deutan

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Protan

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Tritan

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Monochromacy

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Types of Colour Blindness

Colour blindness or colour vision deficiency (CVD) includes a wide range of causes and conditions and is actually quite complex. It's a condition characterized by an inability or difficulty in perceiving and differentiating certain colours due to abnormalities in the three colour-sensing pigments of the cones in the retina. Each cone is responsible for processing different wavelengths of light:

  • Blue: Short Wavelength Light (S-Cone)
  • Green: Medium Wavelength Light (M-Cone)
  • Red: Long Wavelength Light (L-cone)



Red-Green Colour Blindness

Usually when people talk about colour blindness, they are referring to the most common forms of red-green colour blindness, which are genetic conditions caused by a recessive gene on the X-chromosome, but there are other types as well.

Red-green colour blindness can be broken down into two main types:
Protan-type (“pro-tan”), which is a disorder of the first “prot-” type of retinal cones also called the L-cones (red), and Deutan-type (“do-tan”) which is a disorder of the second type of retinal cone also called the M-cones (green).

Types of Colour Blindness

Colour blindness or colour vision deficiency (CVD) includes a wide range of causes and conditions and is actually quite complex. It's a condition characterized by an inability or difficulty in perceiving and differentiating certain colours due to abnormalities in the three colour-sensing pigments of the cones in the retina. Each cone is responsible for processing different wavelengths of light:

  • Blue: Short Wavelength Light (S-Cone)
  • Green: Medium Wavelength Light (M-Cone)
  • Red: Long Wavelength Light (L-cone)



Red-Green Colour Blindness

Usually when people talk about colour blindness, they are referring to the most common forms of red-green colour blindness, which are genetic conditions caused by a recessive gene on the X-chromosome, but there are other types as well.

Red-green colour blindness can be broken down into two main types:
Protan-type (“pro-tan”), which is a disorder of the first “prot-” type of retinal cones also called the L-cones (red), and Deutan-type (“do-tan”) which is a disorder of the second type of retinal cone also called the M-cones (green).

Three Most Common Types of Colour Blindness:

Deutan

Red-Green Colour Blind
Colour Cone Sensitivity: Green

Deuteranomaly is the most common type of colour blindness, affecting about 6% of men. It is characterized by a reduced sensitivity to green light, making it difficult to differentiate between shades of red and green.

Protan

Red-Green Colour Blind
Colour Cone Sensitivity: Red

Protan (“pro-tan”) is the second most common and is characterized by a reduced sensitivity to red light. People with protanomaly have difficulty distinguishing between shades of red and green.

Tritan

Blue-Yellow Colour Blind
Colour Cone Sensitivity: Blue

Tritanomaly is a rare form of colour blindness that affects both males and females equally. It is characterized by a reduced sensitivity to blue light, making it difficult to differentiate between shades of blue and green, as well as yellow and red.

1 in 12 Men and 1 in 200 Women Are Colour Blind

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All Types of Colour Vision

  • A person with normal colour vision can typically perceive up to 1 million different shades of colours.
  • Normal colour-sighted individuals are Trichromats, meaning that they have three different colour sensitive cones in their retina: red, green, and blue.
  • Each of these red, blue, and green cones are sensitive to different wavelengths of light and help to create colour perception.
  • The unique separation and overlap work together to enable those with normal colour vision to see all the colours of the spectrum.
  • It is believed that a person with typical red-green colour blindness often perceives only 10% as many shades of colour as a person with normal colour vision.