Henry Smith and Hamylton, Opticians since 1887

Free Phone: 0800 085 1821


Health & Eyecare - colour vision

The Human eye is capable of experiencing over 190,000 varied colour sensations by using three different receptors (cones) in the retina, each one absorbing different wavelengths of light. The three cones are red, green & blue.

Colour vision deficiency has been traced as far back as the ancient Greeks. The deficiency in colour vision occurs when one or more of the red, green or blue cone receptors is either functioning below its maximum capacity or failing to function at all. Colour vision deficiency most commonly affects the red/green cones in both eyes, unfortunately these colour deficiencies are permanent and cannot be corrected. Men are more likely to be affected by colour vision deficiency, the cause of the problem is hereditary with the responsible gene being carried on the X chromosome.

Colour vision deficiency can also occur through ocular disease such as diabeties, eye disease, cataract and macular degeneration. Patients however usually will only experience the problem in one eye, having difficulty with blue and yellow colours.

Most people won’t notice that they are having difficulty with colours, so the impact of suffering from colour vision deficiency is usually very mild. The impact is more severe on the choice of one’s occupation for example those people wishing to pursue a career for example in aviation, army, police force, etc. must have perfect colour vision. If you fail a colour vision test it does not mean that you are visually handicapped in any way.

As mentioned in ‘your sight test explained’ section a colour vision test is normally given at your first sight test if the Optician feels this is necessary. However if you feel that you are having problems distinguishing colours then please talk to our Ophthalmic Optician.