Colour Vision Deficiency

Overview

Colour vision deficiency means you have trouble seeing some colours or telling certain colours apart. It is often called colour blindness, but most people with it can see many colours — just not all of them in the usual way. It happens when special light-sensitive cells in the eye, called cones, do not work as expected.

Yes. Inherited red-green colour vision deficiency is common. It affects about 1 in 12 men and 1 in 200 women in many populations. Other types are less common.

It affects males more often because the most common inherited type is passed on through the X chromosome, which is one of the thread-like instructions that carry genes. It can affect anyone. Acquired colour vision problems become more likely with age, eye disease, or other health conditions.

Symptoms

Common symptoms

• Trouble telling red and green apart, or blue and yellow apart, depending on the type.
• Some colours look washed out, dull, or very similar to each other.
• Difficulty with colour-coded maps, charts, wires, lights, labels, or clothing.
• You may not realise you see colours differently until you have a test.
• Everyday tasks can take longer, such as matching clothes or reading coloured instructions.

Symptoms in children

• Learning colour names more slowly than expected.
• Trouble with colouring, sorting toys by colour, or matching clothes.
• May be thought to be careless when colour-based schoolwork is hard.
• Can be missed because children often find their own ways to cope.
• Sometimes noticed during school vision checks or a GP visit.

Symptoms in older adults

• A new or worsening problem telling colours apart, especially if it affects one eye or comes on quickly.
• Difficulty with medicines, cooking, reading colour-coded instructions, or choosing clothes.
• Colour vision changes can be linked to cataracts, glaucoma, macular problems, diabetes, or other health conditions.
• May be mistaken for normal ageing, so a new change should be checked.

Causes

Main causes

• Inherited gene changes that affect the cone cells in the eye. This is the most common cause.
• The most common inherited type affects red and green vision and is passed from parent to child.
• Less common inherited types affect blue and yellow vision or other colour pathways.
• Acquired causes include ageing, eye diseases such as cataracts or glaucoma, diabetes, nerve problems, head injury, and some medicines or chemicals.

Risk factors

• A family history of colour vision deficiency.
• Being male, for the most common inherited red-green type.
• Getting older.
• Having an eye disease or a health condition such as diabetes.
• Taking certain medicines or being exposed to certain chemicals without proper protection.
• A head injury or a condition affecting the brain or optic nerve.

When to see a doctor

See a doctor urgently if:

• A sudden change in colour vision, especially in one eye.
• New flashes, floaters, or a shadow across your vision.
• Eye pain, redness, or light sensitivity with vision changes.
• Colour vision changes after a head injury.
• New colour vision problems with diabetes or another long-term condition.

Book a routine appointment if:

• You or your child have always had trouble telling colours apart.
• A child is struggling with colour-based learning at school.
• Colour vision problems affect work, driving, safety, or daily tasks.
• You have a family history of colour vision deficiency and want advice.
• You notice a gradual change in colour vision.

Diagnosis

A GP or eye specialist can check your colour vision with simple tests. They will ask about your symptoms, family history, and any health conditions or medicines. If the problem is new, they may examine your eyes to look for a cause.

Tests that may be done

• Ishihara colour plates — patterns of coloured dots with numbers or shapes.
• Colour arrangement tests — putting coloured caps or tiles in order.
• Anomaloscope — a special instrument that measures how you mix colours.
• Simple colour matching tests for young children.
• A full eye examination, including checking the back of the eye if symptoms are new.

What to expect at your appointment

The tests are quick and painless. You may be asked to look at pictures and say what you see or arrange colours. Results can show the type and severity. If the problem is inherited, no treatment is usually needed, but you can get practical advice. If it is new, your doctor will look for the underlying cause.

Treatment

There is no cure for the common inherited form, and most people do not need medical treatment. The goal is to help you manage daily tasks and to check for underlying eye or health problems if colour vision changes are new.

Self-care at home

• Use good lighting, especially when cooking, reading, or choosing clothes.
• Label items in words, and organise clothes or files by texture, shape, or labels rather than colour alone.
• Use colour-identifier apps or other tools if they help you.
• Ask for help when colour is important, such as with wiring, maps, or safety warnings.
• Tell teachers, employers, and health professionals about your colour vision.

Medical treatments

For inherited colour vision deficiency, treatment focuses on practical help rather than curing the condition. Special tinted glasses or contact lenses, colour-filtering aids, and phone or computer apps may help some people tell colours apart, but they do not give normal colour vision and evidence is mixed. For acquired colour vision problems, the main treatment is to manage the underlying cause — for example, an eye condition or a general health problem. Low vision services and workplace advice can help at home, school, or work.

When is surgery considered?

Surgery is not used to treat inherited colour vision deficiency. If colour vision changes are caused by an eye problem such as a cataract, an eye specialist may discuss whether surgery or another treatment could help the underlying condition.

Living with this condition

Many people develop habits without realising. Use good lighting, label items, and ask for help when colour matters. Tell teachers, employers, and health professionals about your colour vision so they can give information in other ways, such as with words, patterns, or labels.

Lifestyle tips

• Use colour-identifier apps and high-contrast labels.
• Organise clothes, cables, and files by texture, shape, or labels rather than colour alone.
• Ask your pharmacist or doctor to label medicines clearly in words.
• Take extra care with traffic lights, electrical wires, and safety warnings; ask someone if you are unsure.
• Consider career advice if a job requires perfect colour discrimination.

Diet and exercise

No special diet or exercise can cure colour vision deficiency. A healthy lifestyle still matters for general eye health and for conditions such as diabetes and high blood pressure, which can affect vision. Have regular eye checks if you are at risk of eye disease.

Mental health and emotional wellbeing

Colour vision problems can be frustrating, especially at school or work, and can cause worry about safety or being misunderstood. These feelings are valid. Talk to your GP or a counsellor if it is affecting your confidence or mood. If you feel overwhelmed or unsafe, contact your local emergency number or a local crisis support service straight away.

Prevention

The inherited form cannot be prevented, because it is present from birth. Acquired colour vision problems may be reduced by protecting your eyes, managing health conditions such as diabetes and high blood pressure, having regular eye checks, and avoiding known harmful chemicals or medicines without medical advice. Always ask a healthcare professional before stopping or changing any medicine.

Vaccines

There is no vaccine for colour vision deficiency.

Screening programmes

There is no routine screening programme for colour vision deficiency in most places. Colour vision may be checked if you have symptoms, a family history, or a child is struggling at school. Adults with new colour vision changes should have an eye examination.

Complications

If left untreated

• Difficulties at school or work when colour is used to give important information.
• Safety risks with traffic lights, electrical wires, chemical labels, or warning signs.
• Problems with everyday tasks such as cooking, choosing clothes, or reading maps.
• For acquired colour vision problems, the underlying eye or health condition may get worse if not checked.
• Worry, frustration, or low confidence in situations where colour matters.

Long-term outlook

Most people with inherited colour vision deficiency live full and active lives. There is no cure, but practical tools and simple changes help a lot. If colour vision changes are new, finding the cause early can make a real difference. Ask for support — you do not have to manage alone.

Find support

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