Color vision test
Definition
A color vision test checks your ability to distinguish between different colors.
Alternative Names
Eye test - color; Vision test - color; Ishihara color vision test
How the Test is Performed
You will sit in a comfortable position, and your health care provider will explain the test to you. You will be shown several symbols made of colored dot patterns. These dot patterns are on a background of randomly mixed colors.
You will be asked to identify the symbols, if possible.
As you cover one eye, the tester will hold the test plates 14 inches from your face and ask you to quickly identify the symbol found in each color scheme.
How to Prepare for the Test
If your child is to have this test performed, it may be helpful to explain how the test will feel, and even practice or demonstrate on a doll. Your child will feel less anxious about the test if you explain what will happen and why..
If you or your child normally wears glasses, wear them during the test.
With small children, distinguishing a red bottle cap from caps of a different color may be the test.
How the Test Will Feel
The test is similar to a vision test.
Why the Test is Performed
By using these plates, your health care provider can detect, classify, and estimate the degree of defect in your color vision.
In some circumstances, color vision testing is used to evaluate the function of the optic nerve. The optic nerve is the main nerve connecting the eye to the brain. Changes in color vision can often be the first sign of a vision problem.
Normal Results
Normally, you will be able to distinguish all symbols.
What Abnormal Results Mean
This test can determine the following color vision problems:
- Protanopia (difficulty distinguishing between blue/green and red/green)
- Deuteranopia (difficulty distinguishing between red/purple and green/purple)
- Tritanopia (difficulty distinguishing between yellow/green and blue/green)
- Achromatopsia (complete color blindness, seeing only shades of gray)
Risks
There are no risks associated with this test.
Review Date:
2/22/2007
Reviewed By:
Manju Subramanian, MD, Assistant Professor in Ophthalmology, Vitreoretinal Disease and Surgery, Boston University Eye Associates, Boston, MA. Review provided by VeriMed Healthcare Network.
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