Colour blindness, sometimes referred to as Colour Defective Vision (CDV), is when a person cannot see certain colours or they see them differently from others.
The retina, which is located at the back of the eye, contains two types of cells. One type of cells called Rods which help us see at night in shades of black and white, the other cells called Cones help us to see in colour. There are three types of cone cells. A person who is colour blind lacks one of the three types of cone cells.
There are three different types of colour blindness:
- Red - green colour deficiency—people with this kind of colour deficiency are often confused with red and green as they have an absence of red or green cones
- Blue - yellow colour deficiency—this occurs when there is an absence of blue cones
- total colour blindness—is when a person has no cones only rods and can see in black and white only.
Colour blindness can be a misleading term as people who are colour blind are not blind—other than colour they can see as clearly as people who are not colour blind. The most common colours that people have difficulty viewing are greens, yellows, oranges and reds.
Symptoms and characteristics
Symptoms and characteristics of colour blindness may differ depending on the particular type experienced by the person. Common symptoms include:
- difficulties recognising and identifying different colours beyond the age of four years
- inability to separate things by their colour, for example not being able to see red and green but can see blue and yellow
- people with severe colour vision blindness may not be able to see colour at all and can only see shades of grey, black and white.
Workplace adjustments and solutions
There are many difficulties that may arise in everyday work life for people who are colour blind, these include:
- problems with choosing and preparing food, for example a red - green colour blind person may not be able to tell the difference between cooked and uncooked meat or tomato sauce and chocolate sauce
- gardening as flowers would be difficult to distinguish from their leaves, or determining whether a plant is dead or alive and also to know which fruits are ripe
- sport
- driving a car
- selecting clothing
- with electrical goods determining which have red and green LED displays, are in need of a battery charge or if the machine is on standby.
There are various factors which can assist people who are colour blind to better manage their condition and maintain their independence in the workplace. These factors include:
- organising and labelling items such as clothing by colour
- remembering items by their order rather than colour, for example, that the red light is at the top of the traffic light and green is at the bottom
- colour coded work can be done with numbers, letters or other special indicators
- if required, mobility training to assist with getting to and from work, moving around the workplace and work related travel
- evaluation of workplace lighting to ensure it meets Australian standards with the addition of specific task lighting if required for increased brightness or contrast.
The Employment Assistance Fund provides financial assistance for work related modifications, equipment and services to help people with disability to get employment and perform their work as independently and productively as possible. To determine eligibility, please refer to the full guidelines:
There are solutions and adjustments for the following job requirements:
References
Better Health Channel 2010, Colour blindness, State Government of Victoria, Melbourne, viewed 18 August 2011, http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Colour_blindness.
Colour Blind Resource Centre 2000, What is Colour blindness?, Colour Blind Resource Centre, viewed 18 August 2011, http://colourblind.freeservers.com/whatis.htm.
Colour Blind Awareness (no date specified), The Workplace, Colour Blind Awareness, Aylesbury, viewed 18 August 2011, http://www.colourblindawareness.org/about-us/contact-us/.
Colour Blind Awareness (no date specified), Gardening, Colour Blind Awareness, Aylesbury, viewed 12 September 2011, http://www.colourblindawareness.org/colour-blindness/living-with-colour-vision-deficiency/gardening/.
Vision 1 to 1 2000, Defects and Solutions, Vision1to1.com, viewed 18 August 2011, http://www.vision1to1.com/en/HomePage.asp?Article=81&Category=8.
All About Vision 2000-2011, Colour Blindness, All About Vision, San Diego, viewed 18 August 2011, http://www.allaboutvision.com/conditions/colordeficiency.htm.