A color vision test, also known as the Ishihara color test, measures your ability to tell the difference among colors. If you don’t pass this test, you may have poor color vision, or your doctor may tell you that you’re color blind. However, being truly color blind is a very rare condition in which you’re only able to see shades of gray.
The most common type of poor color vision is an inability to distinguish shades of green from red. Poor color vision can be caused by:
| Genetics | Aging | Certain medications and diseases | Exposure to chemicals |
According to Color Blind Awareness, about 1 in 12 men, and 1 in 200 women experience color blindness. The majority of people with color blindness have inherited the condition.
Sometimes, problems with color vision are due to a disease affecting your optic nerve, such as glaucoma. Poor color vision can also be the result of an inherited problem with the cones (color-sensitive photoreceptors) in your retina. The retina is the light-sensitive layer at the back of your eye.
Certain diseases can cause color vision impairment, including:
| Diabetes | Alcoholism | Macular degeneration | Leukemia |
| Alzheimer’s disease | Parkinson’s disease | Sickle cell anemia |
| Your color vision may improve if you receive treatment for the underlying condition |
You may want to have a color vision test if you think your color vision is deficient. If your child is receiving a standard eye exam, it’s a good idea to have them tested for both color vision and visual acuity. This can help address any potential problems early.
If you wear glasses or contact lenses, you should continue to wear them during the exam. Your doctor will ask if you’ve been taking any medications or supplements, if you have any medical conditions, and if there’s a history of poor color vision in your family.
This test has no associated risks, and no special preparation is necessary.