What is the Ishihara Color Blindness Test

When I was a kid, my father used to take me to the optometrist and make me stare at colored dots on a page. He would ask me what color each dot was, and we'd repeat the process for each new page. It wasn't until years later that I learned these tests were called Ishihara tests and that they were used to diagnose color blindness. The Ishihara test is just one type of vision exam which uses different types of images with specific colors in them. While these tests are mostly used by eye doctors to evaluate your ability to see certain colors, they can also be fun ways for your kids (or even yourself) to find out if they have any kind of visual disability!

The Ishihara test is a color perception test for red-green color deficiencies, the first in a class of successful color vision tests called pseudo-isochromatic plates ("PIP").

The Ishihara test is a color perception test for red-green color deficiencies, the first in a class of successful color vision tests called pseudo-isochromatic plates ("PIP"). The plates were invented by Shinobu Ishihara (1886–1976), a professor at Tokyo's Nihon University.

They consist of circular areas with colored dots on them. In each of these areas, one type of dot contains one number (e.g., 1) and another type may contain a different number (e.g., 6). A person with normal color vision will see numbers when looking at those particular dots, while people with certain types of color blindness will not be able to see them.

The test consists of 38 colored plates, but not all the plates are used in a single examination.

The test consists of 38 colored plates, but not all the plates are used in a single examination. The examiner will use different combinations of the plates depending on the results of previous ones. For example, if your vision is normal, you will be shown eight plates with one number or letter on each; if it's abnormal, you'll only see seven or six.

The first plate shows whether or not you have problems detecting red/green color blindness and whether your cone cells perceive hues at different levels (which indicates whether or not you have Deuteranopia). If this result is normal, subsequent tests only involve letters; if it's abnormal then they also include numbers.

Each plate contains a circle of dots appearing randomized in position, size, and color.

The Ishihara Color Blindness Test is a series of plates containing a circle of dots, each plate containing a number or symbol that can be interpreted by those with normal color vision. These symbols are arranged in such a way that they cannot be seen by those with color blindness. The plates are made up of several colored dots which may appear in any order, but they contain one or more numbers/symbols (represented as letters) hidden within them.

If you can see the hidden numbers/symbols on all 10 plates, then your cones should be fine!

Within the pattern are dots which form a number or shape clearly visible to those with normal vision, and invisible, or difficult to see, to those with a red-green color vision defect.

The dots in the pattern are clearly visible to people with normal vision, and invisible or difficult to see for those with a red-green color vision defect.

A person taking the test is asked to identify the number or symbol presented by each picture.

• Ask the patient to identify the number or symbol presented by each picture.

• There are 38 plates, but not all are used in a single examination.

• The plates contain a circle of dots appearing randomized in position, size, and color.

The Ishihara test is one of several sources of diagnostic confusion between protan and deutan types of color vision deficiency.

The Ishihara test is here if you would like to try it now. It is one of several sources of diagnostic confusion between protan and deutan types of color vision deficiency. The test is designed to differentiate between protan and deutan defects, but not to distinguish between those two types from tritanopia or red-green color blindness (protanopia).

Some people with the Ishihara test will be classified as having "normal" results when they may actually have a different type of color vision deficiency that can be more difficult to diagnose with other tests. For example, someone who is missing green cones (deuteranopia) will see all the number plates correctly but report seeing no numbers at all because they cannot detect any greenness in them. A typical person would see the number 5 on this plate as a black circle, while an affected person would report seeing no numbers at all

With this test you (and your optometrist) can find out if you are color blind.

The Ishihara Color Blindness Test is used to diagnose color blindness. It requires you to look at a series of colored dots and identify each symbol. The test consists of many different symbols, including numbers, letters and shapes.

The test is easy to take and you can do it at home if you have access to the Internet; if not, it can also be done in an optometrist's office.

Some people find the test difficult because the colors are often subtle or faded in order for them not to offend people who are not color blind (for example, there is no red on this page). If this happens to you or if your child struggles with this particular part of the exam, don't worry! There are other ways for us professionals to measure your ability—and since I'm just testing for fun here anyway...

Conclusion

If you've taken this test and are concerned about your results, contact your eye doctor. I would recommend going here and taking it for free. It can help determine if you need glasses or other visual correction for this condition.