Colour Vision and Blindness

What is Colour Blindness?

There are some misconceptions about ‘colour blindness’. For a start, it is not true that ‘colour blind’ people can only see black and white. 

Almost all colour blind people can see colour combinations, they just have trouble differentiating between them.

There are different types of colour blindness, but the inability to see any colour at all – a condition called ‘monochromacy’ – is extremely rare.

Colour Blind Awareness

There are approximately 350 million people in the world who do not have normal colour vision and are considered ‘colour blind.’ 

The condition mainly affects males. The condition is found in 8% of men and 0.5% of all women.  About 549,000 Australians (2.2% of the population) are colour blind – or have a colour vision deficiency.

Being ‘colour blind’ has nothing to do with the quality of our vision or how much light we see. It is not a form of blindness, but a deficiency in the way most colours are perceived.

Types of colour vision deficiency

Although there are a number of different types of colour vision deficiencies, they can be separated into three different categories: red-green, blue-yellow and monochromacy colour vision deficiency.

• Red-green

The most common form of colour blindness is red-green colour blindness. People with red-green colour blindness have a hard time telling the difference between the colours red and green. Red-green colour blind people know that a red traffic light is usually at the top and the green lights at the bottom of the traffic lights but they are unable to differentiate between a red light or a green light. 

• Blue-yellow

This type of colour blindness is less common, and more severe. People with this condition can not tell the difference between blue and green or the difference between yellow and red.

• Monochromacy

People with this condition see no colour at all. They have no colour perception. This is total colour blindness. This is the most severe form of colour blindness and is extremely rare.

Causes

Colour vision is made possible by cone cells in the retina, which is a thin wall of tissue at the back of our eyes. The cone cells are sensitive to red, green or blue light, which they combine to give us the wide range of colours we normally see. If one or more of these cone cells is faulty, a person is colour blind.

Colour blindness is usually inherited. If you are born with it, it won’t get any better, or worse. Some people become colour blind as a result of diseases such as diabetes or multiple sclerosis, or they develop the condition over time as they age.

Symptoms

Almost half of all colour blind people are unaware of their condition. This can create a number of problems, especially for children. Many daily activities, such as choosing food, playing sports or reading involve colour.

It’s important to remember that ‘Colour-blind’ people still see colours, but certain colours appear washed out or are confused with other colours. 

If you have difficulty distinguishing between blue and yellow, or red and green, have difficulty seeing light colours, or if you are frequently told by others that the colour you think you are seeing is wrong, it is important to book an appointment with your optometrist to ask whether you could be colour blind.

Treatment

Currently, there is no cure for colour blindness. However, there is help available in special lenses that can enhance colour vision and minimise colour vision deficiency. They are available as contact lenses or glasses. Results vary, depending on the person. While some colour blind people consider these lenses life-changing, others have been disappointed in the results, and claim they don’t work at all.

Colour Blind Adaptation

If you or a loved one is concerned that they don’t have normal vision or has a colour vision deficiency, contact the eye care professionals at Eyecare Plus. They will perform a thorough eye examination and determine if you have normal colour vision or a colour deficiency.

Having a vision deficiency such as colour blindness can be frustrating, but in most cases, it is not a serious threat to vision. 

With patience and practice, people who are colour blind can make lifestyle adjustments that can be made that can help them adapt to the condition.

There are also a number of apps and learning aids available for people who are colour blind. Consult with your local Eyecare Plus optometrist who will provide the best options available to help you make the most of your vision.

At Eyecare Plus Optometrists colour vision testing is a routine part of the eye examinations of every new patient and child.