# Colour Blindness

Source page: https://www.kudretgozistanbul.com/en/treatments/colour-blindness

**Author:** Opr. Dr. Deniz Oygar Baylançiçek | **Medical Approval:** Op. Dr. Nail Sönmez | **Date:** 2026-09-06

> **Summary:** Colour blindness is difficulty telling certain colours or shades apart because the retina's cones lack, or have too little of, the pigments that detect colour. It is usually inherited through the X chromosome, most often as red-green colour blindness, and the inherited form cannot be cured.

## Quick Facts
- **Prevalence:** about 8% of men and about 0.5% of women
- **Most common type:** red-green colour blindness
- **Main test:** Ishihara test
- **Treatment:** inherited colour blindness cannot be treated; filters and lenses may only help some people tell colours apart

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## What It Is
The retina's cones contain three pigment types: red, green and blue. They convert light into signals that the brain interprets as colour. In colour blindness one or more pigments are missing or dysfunctional.

**Types:**
- **Red-green:** red and green and their shades are confused; red lights may look yellow, green leaves brown.
- **Blue-yellow:** blue and yellow confused; blue lights may look grey, yellow objects pale or white.
- **Total (achromatopsia, monochromacy):** all colours seen in shades of grey, like a black and white film.
- **Partial:** some colours look paler or less vivid.

Colour blindness does not usually mean seeing the world in black and white.

## Causes
- Genetics, the most common cause: a recessive X-linked gene, so more common in men.
- Eye diseases such as cataract, diabetic retinopathy and macular degeneration.
- Aging.
- Side effects of some medications; eye injuries (acquired form).

## Symptoms
- Difficulty distinguishing red and green, or blue and yellow
- Colours look pale or dull
- Difficulty identifying the colour of certain objects
- Light sensitivity only in complete colour blindness (achromatopsia)

## Diagnosis
- **Ishihara test:** circles of dots with numbers in a different colour; colour blind people may not see the numbers or see different ones.
- Anomaloscope test
- Farnsworth-Munsell 100 Hue test
- Farnsworth Lantern test

## Treatment
Inherited colour blindness cannot be treated. Special filter glasses and contact lenses do not correct it but may make colours easier to tell apart in some people; coloured contact lenses can reduce some effects in some cases.

## Prices
The price depends on the underlying cause and the procedure; the plan is set after a detailed examination.

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## References
- Color Blindness, NEI
- Colour vision deficiency (colour blindness), NHS