What is color blindness or color vision deficiency?
Color blindness occurs when problems with the color-sensing pigments in the eye cause difficulty or an inability to distinguish colors.
Most color blind people don’t know the difference between red and green. Separating yellow and blue can also be problematic, but this color blindness is less common.
This condition can range from mild to severe. If you are completely color blind this is called achromatopsia, you will only see in grey or black and white. However, this condition is very rare.
Most people with color blindness see the following colors on color maps more than red, green, and teals:
What are the types of color blindness?
There are three main types of color blindness.
In a way, the person has a hard time distinguishing between red and green. In another type, it is difficult for a person to distinguish between yellow and blue.
The third type is called achromatopsia. The person with this shape does not perceive any color, everything appears in grey or black and white. Achromatopsia is the most common form of color blindness.
Color blindness can either be inherited or acquired.
Inherited color blindness
Inherited color blindness is more common. This is due to a genetic defect. This condition runs through the family. This condition is also more common in people who have color-blind relatives.
Acquired color blindness
Acquired color blindness develops later in life and can affect men and women equally.
Diseases that damage the optic nerve or the retina of the eye can cause acquired color blindness. For that reason, you should alert your doctor if your color vision changes. It might indicate a more serious underlying issue.
How common is color blindness?
Color blindness is more common in men. Women are more likely to carry the faulty chromosome that causes color blindness, while men are more likely to inherit the condition.
According to the American Optometric Association, 8 per cent of white men are born with color vision defects compared to 0.5 per cent of women of all races.
A 2014 study of color blindness in Southern California preschool children found that impaired color vision was more common among non-Hispanic white children and more common among black children.
Achromatopsia affects 1 in 30,000 people worldwide. Of these, up to 10 per cent do not perceive any color.
What are the symptoms of color blindness?
The most common symptom of color blindness is a change in your vision. For example, it may be difficult to distinguish between the red and green of a traffic light. Colors may seem less bright than before. Different shades of a color may all look the same.
It is often apparent at a young age when children are learning their colors. In some people, the problem goes undetected because they’ve learned to associate specific colors with certain objects.
For example, they know that grass is green, so they call the color they see green. If symptoms are very mild, a person may not realize that they don’t see certain colors.
You should consult your doctor if you suspect you or your child is colorblind. They’ll be able to confirm the diagnosis and rule out other more serious health issues.
What causes color blindness?
The eye contains nerve cells called cones, which allow the layer of light-sensitive tissue at the back of the eye to retain colors.
The three types of cones absorb different wavelengths of light and respond to each type of red, green, or blue. Cones are sending information to the brain to distinguish colors.
If one or more of these cones on the retina are damaged or missing, it can be difficult for you to see colors correctly.
Most of the defect in color vision is inherited. It usually passes from mother to son. Hereditary color blindness does not cause blindness or other vision loss.
You may have color blindness as a result of retinal disease or injury.
With glaucoma, the internal or intraocular pressure of the eye can be very high. The pressure damages the optic nerve, which transmits signals from the eye to the brain so you can see. As a result, your ability to distinguish colors may decrease.
According to the Journal of Investigative Ophthalmology & Visual Science, people with glaucoma have not been able to distinguish between blue and yellow since the late 1800s.
Macular degeneration and diabetic retinopathy cause damage to the retina, where the cones are located. This can causes color blindness. In some cases, it can lead to blindness.
If you have cataracts, the lens in your eye will gradually change from transparent to opaque. As a result, your color vision may be blurred.
Other diseases that can affect vision include:
- Parkinson’s disease
- Alzheimer’s disease
- Multiple sclerosis
Certain medications can cause changes in color vision. These include the antipsychotic medications chlorpromazine and thioridazine.
The antibiotic ethambutol (Myambutol), which treats tuberculosis, may cause optic nerve problems and difficulty seeing some colors.
Looking at the colors is subjective. It is impossible to tell if you see red, green, and other colors like people with perfect vision. However, your ophthalmologist can evaluate this condition with a regular eye exam.
The test involves the use of special images called pseudoisochromatic plates. These images are made with colored dots that have numbers or symbols.
If you are color blind, you may not see the number or see a different number.
It’s important for kids to get tested before starting school because early childhood education involves identifying colors.
What is the outlook for people with color blindness?
If It’s occurs as the result of illness or injury, treating the underlying cause may help to improve color detection.
However, there’s no cure for inherited color blindness. Your eye doctor may prescribe tinted glasses or contact lenses that can assist in distinguishing colors.
People who are colorblind often consciously apply certain techniques or use specific tools to make life easier. For example, memorizing the order of the lights from top to bottom on a traffic light removes the need to distinguish its colors.
Labelling clothing can assist in matching colors properly. Some software applications transform computer colors into those that colorblind people can see.
Inherited color blindness is a lifelong challenge. While it may limit prospects for certain jobs, such as working as an electrician who must tell the difference between color-coded wires, most people find ways to adapt to the condition.