Partial color blindness test is a medical examination procedure to determine whether the eye is able to see or distinguish colors well. This check often done to obtain a certificate of color blindness required as a condition of applying for a job or continuing studies.
Color blindness is a visual disorder characterized by the inability to see or distinguish certain colors. In total color blindness, the eye is unable to see color at all and only gray is visible.
While partial or partial color blindness is a condition when the eye cannot see certain colors well, for example, it cannot distinguish red from green.
Types of Partial Color Blindness
Partial color blindness is divided into two types and each has different symptoms. Here is the explanation:
red-green color blindness
Red-green color blindness is the most common type of color blindness experienced by color blind people. There are several types of red-green color blindness, namely:
- ProtanopiaProtanopia is a type of partial color blindness that occurs when a person sees red as appearing black. People with this type of color blindness may also see the color orange green to yellow.
- ProtanomalyProtanomaly sufferers will see the colors orange, yellow, and red, turning green. The visible green color is also not as bright as the original color.
- deuteranomalyA person is said to be deuteranomaly if he sees green and yellow looking like red. Sufferers also have difficulty distinguishing between purple and blue.
- DeuteranopiaDeuteranopia is a condition in which the eye sees green to beige and red to yellow-brown.
Blue-yellow color blind
Blue-yellow color blindness is a less common type of color blindness than red-green color blindness. There are 2 types of blue-yellow color blindness, namely:
- TritanomalyThis type of partial color blindness makes a person see blue as green. This condition also often makes it difficult for sufferers to distinguish pink from red or yellow.
- TritanopiaTritanopia is a condition in which the eye sees blue colors such as green and yellow colors such as light gray or purplish.
This Is What To Do During Partial Colorblindness Test
There are several methods of examination that can be done as a partial color blindness test, namely:
Test Ishihara
This test is one of the most common types of partial color blindness tests performed. This examination is practical and does not require complicated medical equipment.
In the Ishihara test, the patient will be invited to sit in a room with sufficient lighting. The doctor will place a card called the Ishihara card in front of the patient. The image on this card is composed of colored dots that form a pattern in the form of numbers, letters, symbols, or grooves.
Next, the doctor will ask the patient to close one eye and read the letters or numbers on the card. In addition to reading numbers or letters, patients are also asked to trace certain color grooves on the card with their fingers. After one eye is completed, the same test will be performed on the other eye.
Anomalyoscope
During this test the patient will be asked to look into an instrument similar to a microscope. This tool is called anomalyoscope. When looking into the device, the patient will see two circles that are divided into two colors, namely red-green on one side and yellow on the other.
After that, the patient will be asked to adjust the color by turning a button on the tool until the colors on the two circles look united into the same color.
Colored wool yarn test
This partial color blindness test method is also known as the Holmgren test. This examination uses wool yarns of various colors that have been specially designed.
In this examination, the doctor will ask the patient to take a thread with a certain color. If the patient can take the woolen thread according to the color instructed, then the patient is judged not to have color blindness.
However, the results of this examination have a lower level of accuracy than other partial color blindness tests.
To determine whether you are color blind or not, you can consult an ophthalmologist for a color blind test. After undergoing an examination, the doctor will determine whether you can see colors normally or not.