Color Blindness
What is color blindness?
If you have color blindness, it means you see colors differently than most people. Most of the time, color blindness makes it hard to tell the difference between certain colors.
What causes color blindness?
In the retina, there are two types of cells that detect light. They are called rods and cones. Rods detect only light and dark and are very sensitive to low light levels. Cone cells detect color and are concentrated near the center of your vision. There are three types of cones that see color: S, M and L cones. The brain uses input from these cone cells to determine our color perception.
Color blindness can happen when one or more of the color cone cells are absent, not working, or detect a different color than normal. Mild color blindness happens when all three cone cells are present but one cone cell does not work “right” or normally compared to most people. It detects a different color than normal.
The most common kinds of color blindness are genetic, meaning they’re passed down from parents. It is generally passed down from the X chromosome, so the mother’s side of the family tends to have male relatives who are color blind as well.
Color blindness usually affects both eyes equally and remains stable throughout life.
What are the types of color blindness?
There are different degrees of color blindness. Some people with mild color deficiencies can see colors normally in good light but have difficulty in dim light. Others cannot distinguish certain colors in any light.
The most common type of color blindness is “red-green”. This does not mean your child cannot see red or green, but that certain shades of colors will be confused with each other. This is because either the “M” cone or the “L” cone is missing or shifted so that there is less overlap between the cone cells.
The most severe form of color blindness, in which everything is seen in shades of gray, is uncommon and associated with poor vision and eye shaking (nystagmus). Color blindness can be secondary to underlying eye disease but this is associated with other signs and symptoms.
What are the symptoms of color blindness?
The main symptom of color blindness is not seeing colors the way most people do. If you’re color blind, you may have trouble seeing:
The difference between colors
How bright colors are
Different shades of colors
Symptoms of color blindness are often so mild that you may not notice them. And since we get used to the way we see colors, many people with color blindness don’t know they have it.
Did you know?
Everyone sees color a little differently — even people who aren’t color blind
About 1 in 12 men are color blind
About 1 in 200 women are color blind
If your “M” cone is missing or shifted, you have a “deutan color deficiency” (this is the most common color blindness in the world)
If your “L” cone is missing or shifted, you have a “protan color deficiency”
There are different color blind tests we use during the exam that let use determine the severity and type of color blindness you have. You can even check if you’re color blind online. Here is an example of a online color blindness test.
What's the treatment for color blindness?
There’s no cure, but special glasses and contact lenses can help. Most people who are color blind don’t have problems with everyday activities. It is not unusual to be diagnosed well into adulthood. Children with color blindness may need help with some classroom activities, and adults with color blindness may not be able to do certain jobs, like being a pilot or graphic designer. Teachers should be informed of the color blindness to avoid assigning classwork that involves identifying colors (and instead use shapes/numbers/letters) since children with color blindness tend to confuse colors with each other.
