Color Blindness

Color blindness occurs when there is damage to or functionality issues with the cone cells located in the retinal tissue.

The two most common types of color blindness:

1.Congenital/inherited
2. Acquired due to pathology or trauma.

There are several different types of color vision tests:

• Ishihara test 
• Pseudoisochromatic Plates
• Farnsworth- Munsell D-15 or D-100
• Waggoner Computerized Color Vision Test

These are just a few examples. Typically offices will use the Ishihara test for screening, then move to more sophisticated testing if positive. 

So, this is the Ishihara test. You'll see the number of plates. You'll give the patient about 3 seconds to respond and then you can move on to the next page. Remember, there is no coaching, no touching, or tracing. I would show anywhere from 5 to 7 images, so this is about 3 to 4 pages per patient.

“Mrs. Davis, this test allows us to assess your ability to see small differences in colors. Usually color deficiency is an inherited trait, but occasionally it indicates an issue with your optic nerve or retina.” 

For documentation purposes, you will have to document the results for the right and the left eye and what type of test was used.

Common patient feedback and responses: some patients may state that they do not feel that they're getting an adequate amount of time for this test and some patients may report that this test is difficult or that they are unable to see any numbers. Again, remind the patient that this is a threshold test and if they can't see it, that's okay.