The photoreceptor cells of the retina are the ones that allow the visual system can distinguish the colors of the images. The partial or total inability to see colors is known as colorblindness, a genetic condition that affects men more often than women.
The degree of affectation of this condition is very variable and, to determine it, it is necessary to perform the color blind test. Currently, there are various diagnostic tools that we use to detect this condition and determine if the patient has trouble discerning all the colors or only some shades.
En Área Oftalmológica Avanzada We explain what the color blindness test consists of and who should undergo this procedure.
What is color blindness?
Color blindness is a hereditary disease of genetic origin that affects the ability of people to distinguish colors. In most cases, between the different colorblind color types, people with this condition they cannot differentiate red and green colors, although some people may have problems distinguishing blue tones.
Color blindness affects men more often than women, and it is more common in those of European descent. This disease is due to a genetic cause and causes the malfunction of the cells of the retina, called cones, which are sensitive to color. When this happens, the patient may perceive the colors in different shades or not at all.
Performing the color blindness test is very important for determine the degree of affectation of the patient and find out what are those ranges of colors that you cannot differentiate.
Color blindness can be classified as follows:
- protanopia: happens when there is complete absence of photoreceptor cells of the retina
- deuteranopia: occurs when the retina has absence of green-sensitive photoreceptor cells.
- tritanopia: it is less common and occurs when the retina has absence of blue-sensitive photoreceptor cells.
Types of color blindness test
There are several tests to diagnose color blindness. However, today it is still used Ishihara test with more frenquency. The color blindness test are:
Protan and Deutan test
Helps diagnose the type and severity of color blindness. This test also makes it possible to determine the best lens to correct the patient's vision.
Tritan test
Allows diagnose the absence of receptors sensitive to blue light. This test diagnoses the condition that is causing problems seeing color ranges well and its severity.
Color matching game
It is a game that helps better understand the characteristics of the perception of colors in a patient. It consists of reconciling the basic colors by viewing an image where the saturation and lighting are constant, but the hues vary. To pass the level, the patient must correctly identify the 7 colors.
Farnsworth–Munsell 100
El Farnsworth test helps quantify and identify color blindness. The test is made up of four cards that contain small discs of different colors. Each tile has its reference disk, which is colored at each end.
To do the test, the patient must order the discs on the card, in order to create a gradual composition of colors.
Reverse color blind test
In this test, the patient must see a card, where there is a certain figure or shape. People with normal color vision do not notice anything when they see them, while those with color blindness, they can easily identify the figure on each card.
Ishihara test, the best known test
The test is made up of 38 cards that contain points of different colors. On each card the dots form a number that patients with normal vision quickly identify and color blind patients may confuse or not appreciate it.
The Ishihara test was created by Dr. Shinobu Ishihara, a professor at the University of Tokyo in 1917 and, to date, is the color blindness test most used to diagnose this alteration.
Let's do a test as an example:
By looking at the circle, a person without color blindness will be able to distinguish the number 5 inside it. On the contrary, if the person does not distinguish any number, it means that he suffers from color blindness.
Color blind test in children, how to detect it in time?
Color blindness it is usually a congenital condition, that is, it is present from birth, but it can also contract over time. Many children with color blindness are unaware that they have this disease because the colors they see in the images are the ones they have always seen.
What is the test for color blindness in children? Usually it is the parents and teachers who determine that a child tends to confuse them when playing with their toys, painting or doing homework. In most cases, it is diagnosed when the little one is learning colors.
If a child has difficulty correctly identifying colors, It is important to take it to pediatric ophthalmologist and perform a color test.
Who should get a color blindness test?
color blindness test should be done to all those people who present a problem to identify the colors or that you want to dedicate yourself to a profession where this perception is essential. Some examples are pilots, electricians, designers, firefighters, technicians, police, etc.
Some jobs require more than others that the personnel who occupy them have a good perception of colors. This can cause fear in the patient, since most color blind are not aware of their color blindness and do not understand that this condition can significantly interfere with their professional life.
Glasses for color blind people can help the patient differentiate between one color and another. However, it is important to note that there is currently no definitive treatment or cure for color blindness.
En Área Oftalmológica Avanzada We are experts in color blindness testing. Do not hesitate to contact us if you suspect that you have problems differentiating the colors. We will be happy to assist you!
