Color tests are a diagnostic instrument used in ophthalmology to detect any alteration that is affecting the correct perception of colors in vision.
Thanks to the color tests in ophthalmology, the colorblindness and in Área Oftalmológica Avanzada, we are going to explain what the most used color tests are.
What color test is there in ophthalmology?
Color tests in ophthalmology are used to determine if the patient has any problem in the color vision, either due to some congenital problem in the photoreceptor cells or because there is some complication in the functioning of the optic nerve.
Ishihara test
El Ishihara test It is one of the most widely used color tests for diagnosing color blindness, but it is also effective in detecting abnormalities in the functioning of the optic nerve, such as optic neuritis or problems related to eyes in thyroid patients.
The Ishihara test consists of showing the patient a series of cards containing color points of different sizes.
Each of the Ishihara plates has a visible number for those with normal color vision, but it is difficult to perceive for those who suffer from visual pathology. The test consists of finding out if the patient perceives the numbers and, for this, he must have a good color perception.
Farnsworth test
El Farnsworth test It is one of the color tests easier to perform and consists of sitting the patient 50cm away from a transparent box that contains a kind of black buttons with a color in the center. Then, the patient must order these buttons by color.
In addition, the test also contains 15 discs with numbers that make up an incomplete color circle. The patient should try to order the discs so that the doctor can assess the correct perception of each color.
What are they for?
Color tests in ophthalmology are essential to determine if a patient has colorblindness, optic nerve disease or any problem that limits your visual ability to distinguish colors.
Color tests help diagnose the following types of color blindness:
- protanopia. The red spectrum is shortened due to the lack of cones responsible for the perception of red color and causes the blue-green spectrum to be perceived as gray.
- deuteranopia. The green color is perceived as gray due to the absence of cones that differentiate green. Therefore, problems in the perception of blue and yellow can also be identified.
- achromatopsia. Alteration in which the eye can only perceive the colors white, black, gray and all its ranges. Achromatopsia is also known as complete color blindness, but it should not be confused with color blindness because, in this case, the problem lies in the identification of red and green tones.
- tritanopia. It occurs when the patient has all three types of cones, but they present functional problems that cause them to confuse one color with another. Most colorblind people have three types of cones, but they perceive colors in an altered way.
If you haven't checked your visual health for a long time, don't hesitate to contact us. In Área Oftalmológica Avanzada We are delighted to do the color test in ophthalmology. Call us!
