Did you know colour blindness affects approximately 8% of men and less than 1% of women?

Colour blindness is not a form of blindness. Colour blindness is a deficiency in the way you see colour. People who are colour blind can see colors, but have difficulty distinguishing between certain colors, such as red and green or blue and yellow.

Red and green colour deficiency is the most common form of colour blindness. Blue and yellow colour deficiency usually affects men and women equally. In addition, there is also a small group of people who have a condition called monochromatism which only allows them to see black and white.

What Causes Colour Blindness?

Colour blindness is a genetic condition. Colour blindness occurs when light-sensitive cells in the retina fail to respond to variations in wavelengths of light that enable people to see an array of colours.

Photoreceptors in the human retina are called rods and cones. There are approximately 100 million rods in the human retina. Rods are located outside of the retina and control black and white vision in low-light conditions. They are sensitive to light and are incapable of perceiving colour. There are approximately 6 to 7 million cones in the human retina. Cones are located in the central retina and colour vision.

Inherited forms of colour blindness are related to deficiencies in certain types of cones. There are other causes of colour vision defects or loss besides differences in genetic makeup:

Parkinson’s Diseases (PD)

PD is a neurological disorder so light-sensitive cells in the retina may be damaged and cannot function properly.


A cataract is a clouding of the eye’s natural lens which can wash out color vision.

Tiagabine for Epilepsy

Tiagabine is an anti epileptic drug which has shown to reduce colour vision in approximately 41% of those taking the drug.

Leber’s Hereditary Optic Neuropathy (LHON)

LHON is a inherited optic neuropathy which can affect even carriers who don’t have other symptoms but do have a degree of colour blindness.

Kallman’s Syndrome

Kallman’s Syndrome is a inherited condition which involves failure of the pituitary gland. This can lead to incomplete or unusual gender-related development and colour blindness can be one symptom of this condition.

Can You Treat Colour Blindness?

Unfortunately, there is no known cure for colour blindness. However, contact lenses are available with filters to help colour deficiencies. For example, people with red and green colour blindness are able to use special lenses.

New Optical Palace is your Optometrist serving the Kitchener and Waterloo Area. We offer eye exams and have a wide variety of prescription glasses, sunglasses and contact lenses.