Colour is detected by specialised cells of the retina – the cones. These cells are also responsible for vision in bright light and discrimination of fine detail. The other light-sensitive cells found in the retina – the rods – are responsible for vision in low light situations but only register black, white and grey.
Colour vision impairment affects approximately 8% of males and 0.4% of females with normal vision.
The most common colours that people have difficulty with are green, yellow, orange and red. Very few people have total colour blindness – the inability to detect colour at all.
Some, but not all students with vision impairments, will have difficulty distinguishing certain colours.
Colour vision impairment can cause difficulties such as:
- inability to make use of colour coding in learning materials
- inability to distinguish and name coloured pencils and other coloured items
- inability to distinguish red and green traffic lights (except by position)
- difficulties with choosing matching clothes
- [some professions (e.g. pilots) require good colour vision]
You can have your eyes tested for colour vision impairment by an optometrist or take a look at an online colour vision test.
For more information visit: Vision and Vision Impairment.