Colour Vision
Having Colour Vision is truly a blessing. Seeing all the different colours is not something we are all able to do. There are people who have colour deficiencies, also erroneously referred to as “COLOUR BLINDNESS”, which is not correct as the name implies. It is not actually a “blindness” or loss of vision but rather a decreased ability, or “reduced” ability to see colour or perceive colour differences under normal lighting conditions. Colour vision perception is the result of the normal functioning of the three colour receptors at the back of the eye. They are merely unable to see specific colours, or have a reduced sensitivity to see specific colours, Namely RED, GREEN, BLUE, or in very rare cases ALL the colour receptor cells.
It is mainly men who have a colour deficiency, although very rarely, occasionally woman. It is interesting though that the Females carry the colour deficiency gene, but this mainly manifests in their sons.
You might be surprised to realize that we can not actually see colours at night. Try going outside on a bright moonlight night and look around in the garden to notice that your colour perceiving ability is almost reduced to black and white and varying shades of grey. Did you ever notice this before?
Colour Vision Deficiencies can be identified by the Particular Colour Receptor Cells that are involved namely:-
RED receptor cells absent:-
Complete absence of RED receptors – Protanopia. This is how an Individual would see the picture below. This individual would see colours perceived by two of the receptor cells. This condition is quite common, and affects approximately 1% of Males, and is extremely rare in Females.
Reduction in RED cell sensitivity:-
Protanomaly. This is how an Individual would see the picture below. This individual would see colours perceived by two of the receptor cells, thus colours are not perceived correctly by all three receptors. This condition is fairly common, and affects approximately 1% of Males, and 1:3500 Females
Green receptor cells absent:-
Complete absence of GREEN receptors – Deuteranopia. This is how an Individual would see the picture below. This individual would see colours perceived by two of the receptor cells. This condition is quite common, and affects approximately 1% of Males, and is extremely rare in Females
Reduction in GREEN cell sensitivity:-
Deuteranomaly. This is how an Individual would see the picture below, thus colours are not perceived correctly by all three receptors. This is the most common Colour Deficiency and affects 5% of Males and 1:250 Females.
BLUE receptor cells absent:-
Complete absence of BLUE receptors – Tritanopia. This is how an Individual would see the picture below thus colours are perceived by only two of the receptor cells. This condition affects 0.0001% of Males and Females.
Reduction in BLUE cell sensitivity:-
Tritanomaly. This is how an Individual would see the picture below , thus colours are not perceived correctly by all three receptors. This is a very rare condition and affects 1:500,000 Males and Females
All receptor cells absent:-
Complete absence of ALL receptors – Achromatopsia. This is how an Individual would see the picture below thus colours are perceived in black and white and varying shades of grey only.This condition is extremely rare, and occours only in 1:3,300,000 individuals. Typically these individuals usually also have very poor vision.
All content and images with kind permission of wwwSpectrumeyecaresoftware.com