1. Colour vision

2. Colour vision fact Defective colour vision is not ‘colour blindness’

3. A normal eye has three colour receptors For red, green and blue light Responses are relayed to the brain Here they are mixed together to perceive many thousands of colours

4. Colour vision defects One receptor is missing One receptor is abnormal Two or even three receptors are missing –More rare –More serious problem

5. Defective colour vision is common 1 in 12 men (8 percent) 1 in 200 women (0.5%)

6. Defective colour vision causes Colour matching problems Colour naming problems Inability to perceive brightness of colours

7. Defective colour vision is inherited Present at birth and remains unchanged There is no treatment

8. Everyday problems Recognising colour of traffic lights Seeing coloured flowers on trees Judging ripeness of fruit Knowing when meat is cooked

9. Careers that require normal colour vision Airline pilot Air traffic controller Train and tram driver Policeman Fireman Careers in the defence forces Seafarer

10. Normal colour vision is helpful for Painters and decorators Fashion industry Colour mixers Medicine Artists

11. Colour is used in schools for teaching purposes Therefore all children should have their colour vision tested

12. Testing for colour vision problems Ishihara test Very reliable Takes a few minutes > 3 errors means fail Follow up is necessary

13. Defective colour vision varies in severity The Ishihara test doesn’t measure the extent of the defect Further tests are required to assess this Follow up can be provided by an optometrist or ophthalmologist

14. Optometrists Provide a comprehensive visual examination Detect and diagnose eye health problems Prescribe and supply glasses and contact lenses when required Diagnose and treat eye coordination and focussing problems

15. Optometrists Are university educated and undertake continuing professional education No referral is required Eye tests attract a medicare rebate

16. To find an optometrist Optometrists Association Australia www.optometrists.asn.au Yellow Pages