Colour Vision Deficiency
What Is Colour Vision Deficiency?
Colour vision deficiency will manifest in two main ways:
- The patient will confuse some colours
- They will not see some colours as brightly as people with normal colour vision
It is very rare for a person to not see any colour at all. Hence very few people are actually “colour blind”. Males are more likely to have a colour vision deficiency with approximately 8% of males affected. Only 0.5% of females have colour vision problems. The most common form of colour vision problem is being unable to distinguish between different shades of red and green.
What Causes It?
99% of colour vision disorders are genetically inherited. A few people develop colour vision deficiencies through aging, disease or trauma. Every colour in the visible spectrum corresponds to a unique wavelength of light, similar to a unique radio signal frequency. The light receptor cells in the retina contain light sensitive pigments called photopigments. A “red” photopigment responds most strongly to orange and red colours, a “blue” photopigment responds best to violets and blues, and a “green” photopigment responds best to yellows and greens. In people with colour vision deficiency, some of the receptor cells in the retina respond to the wrong wavelengths.
How Do We Assess It?
Your Envision Optical optometrist will utilize a number of pieces of equipment to administer simple and painless tests to reveal any colour vision problem you may have. Detailed categorization of colour vision deficiencies may require referral for tertiary testing.
Currently there is no cure for colour vision deficiency. Some specialized lenses are available that alter the colour perception of the world to give temporary “normal” colour vision. They are much like a specially tinted pair of glasses with different shades of tint for each individual person.
The major impact of colour vision problems is through the vast amount of visual information we receive that is colour coded. The learning of children can be hampered by colour vision problems. Many occupations such as pilots, military personnel, drivers, fashion designers and painters must be able to accurately discriminate between colours and therefore will be potentially ruled out as career choices by a colour vision deficiency. Also traffic lights and other warning signals may be difficult to decipher for people with Colour Vision Deficiency.