Colour blindness (colour vision deficiency) occurs due to a deficiency or improper functioning of special nerve cells in the retina. This results in certain colours appearing differently than usual. Generally, most people who suffer from colour vision deficiency are born with it.
What is Colour Blindness?
Colour blindness or colour vision deficiency refers to an individual’s inability to see colours in their true form. A colour blind person cannot view colours the way a normal individual can, who does not have colour blindness. This is a pretty common vision problem and is predominantly found in males.
Your vision is the result of a complex process that involves your eyes and brain working together in order to convert light into the visuals you see. Special nerve cells (photoreceptors) in your retina convert light into nerve signals that travel to your brain and help in creating vision.
Cones are a type of photoreceptor cells that help you with colour perception – they help you recognise and differentiate between colours. While it may not be visible to the naked eye, light is made up of tiny, coloured waves. Here are 3 types of cones responsible for identifying a different colour (wavelength) of light:
- Red-sensing cones (L cones)
- Blue-sensing cones (S cones)
- Green-sensing cones (M cones)
Typically, with the help of all three cones, your eyes can identify and communicate information that informs your brain about different colours. Every colour can be used to create newer shades and combinations. Colour vision deficiency occurs when an individual is born without enough cones or dysfunctional cones.
Most of us are familiar with the concept of colour blindness. However, it’s important to acknowledge that “colour blindness” is a bit of an outdated term. “Colour vision deficiency” is more accurate and typically used by healthcare providers across the globe.
The word “blindness” implies that you can’t see any colour. But that is not correct, even if you suffer from colour vision deficiency. CVD just means the affected individual will see colours differently from most people. In short, generally, CVD is more of an altered perception of colours than a complete inability to see colours.
Colour Blindness Causes
Generally, colour blind people are born with the condition (inherited colour blindness). This happens owing to a shared genetic change that’s passed down through generations – this change can lead to dysfunctional or missing cones that cause colour vision deficiency.
While it is rare, some people develop the condition later in life – owing to an accident or injury that damages the cones in their retina. Some causes include:
- Age-related macular degeneration, glaucoma, or cataracts
- Diabetic-retinopathy
- Eye injury or trauma
- Side effects from medication
- Environmental factors
Colour Blindness Symptoms
The absence of complete colour vision is the most prominent symptom. However, with most types, the symptoms are more subtle than a complete inability to see colours. Here are some common symptoms:
- Difficulty differentiating between some colours
- Inability to see the full depth or brightness of colours
- Seeing a different shade or variation of colours
Types of Colour Blindness
Red-green Colour Deficiency
This is the most common type of colour blindness. This causes difficulty in seeing colours or shades that have green or red in them. The subtypes include:
- Protanomaly: All 3 cones are present, but red-sensing cones do not function properly.
- Deuteranomaly: All 3 cones are present, but green-sensing cones do not function properly.
- Protanopia: Red-sensing cones are missing. Difficulty in seeing red or related shades.
- Deuteranopia: Green-sensing cones are missing. Can only see blue and gold. Difficulty in differentiating between green-yellow and red-green.
Blue-yellow Colour Deficiency
This happens when the blue cones are either missing or dysfunctional. This type of colour blindness is rarer than red-green. Its subtypes include:
- Tritanopia: Missing blue cones. Inability to see shades of blue. Affected individuals can only see red, pink, and lavender hues.
- Tritanomaly: All 3 cones are present, but blue-sensing cones do not function properly. Blue shades appear green. There is an increased difficulty in seeing yellows, too.
Blue Cone Monochromacy
This is the most rare type of colour blindness. This happens when an individual possesses neither red nor green-sensing cones. Since the retina only has blue-sensing cones, it is hard to differentiate between any colours at all. All colours appear grey.
Blue cone monochromacy is typically accompanied by eye conditions, such as:
- Amblyopia (lazy eye)
- Myopia (nearsightedness)
- Uncontrollable eye movements
- Light sensitivity
Rod Monochromacy
Also known as Achromatopsia, this condition can be referred to as complete colour blindness. Individuals suffering from achromatopsia are not able to see any colours. This condition is also accompanied by impaired vision and other complications.
Colour Blindness Management and Treatment
There is no treatment for inherited colour vision deficiency. Acquired colour blindness, however, can be treated if the underlying cause is treated. However, if the cones get damaged, your vision may be affected permanently.
Colour blindness glasses do help restore colour vision to some extent by facilitating more vivid colours. They essentially amplify the affected individual’s natural colour vision. However, these glasses can neither treat nor cure the cause of the colour vision deficiency.
However, if you notice sudden changes in your vision and colour perception, you should schedule an appointment with a trusted eye specialist in Chandigarh.
Frequently Asked Questions
How to tell if I have colour blindness?
If you experience extreme difficulty in differentiating between colours or if you find it hard to identify colours that others can instantly recognise, you might be suffering from colour vision deficiency.
It is best to get a proper diagnosis from an eye specialist, who can then prescribe you management techniques and corrective measures to help alleviate some symptoms.
Does colour blindness worsen with age?
Inherited colour vision deficiency does not become worse with age. However, age-related eye conditions can sometimes impact colour vision, resulting in acquired colour blindness.
Does colour vision get better with age?
There are no scientific studies that back the notion that colour vision gets better with age. However, many individuals with inherited colour blindness report that their colour vision improved with age. That could be owing to habitual competence and improved ability to tell colours apart, rather than an actual improvement in the condition.
