Not so long ago, new rules for medical examination drivers, namely: in addition to the updated form received by the applicant for drivers after passing the commission, the order itself and the list of doctors giving the go-ahead for the right to drive a vehicle have slightly changed. So, today, the conclusion of such doctors as ENT and a neurologist will be mandatory only for truck drivers. A visit to an ophthalmologist remains unchanged, mandatory for everyone, regardless of the category received. Checking color perception, vision testing are an integral test for everyone who wants to drive vehicles. If everything is clear with visual acuity, then let's figure out what a color perception test is for drivers and whether it is possible to prepare for this test.
What is color perception?
Color perception is the ability of the human eye to distinguish between a range of different colors. Retinal cone cells are responsible for the perception of colors. Normally, a person has three receptive colors of the apparatus in the eye, which are excited to varying degrees under the influence of various radiation wavelengths (red, green and blue). If the eye is not able to distinguish one color from another, that is, if the retina is not able to "catch" the difference in the wavelength of radiation, then there is a disorder of color vision. Like most diseases known to science, color perception disorder can be either acquired (observed in diseases of the optic nerve and retina), or congenital. Congenital inability to distinguish colors - color blindness - is a serious, insurmountable obstacle to obtaining a driver’s license.
Color Sensing Diagnostics
So, how is color perception testing for drivers? To determine color blindness among drivers in the arsenal of ophthalmologists there is a special method that allows you to accurately identify this pathology. This method includes a variety of polychromatic tables for checking color perception for drivers, namely: Ishihara, Fletcher-Gambling, Stilling, etc. However, the most common diagnostic method are Rabkin tests. Such tables are some drawings collected from dots and circles of various diameters and colors. A person who has deviations in the perception of color, simply can not distinguish and distinguish some colors from others, therefore, can not see the latent image.
The book for checking vision for the driver’s color sensation consists of a set of Rabkin tables that differ in “purpose”: for example, the first 27 pictures are designed to identify color vision disorders, as well as its shape. The remaining images in the book for checking the color perception of drivers are needed to confirm and clarify the diagnosis.
Color Perception Test Conditions
To obtain a reliable result of checking color perception for drivers, it is necessary to observe a number of conditions:
- Research is forbidden to be carried out under artificial lighting of the room. The well-being of the diagnosed guarantees an accurate result.
- The examinee should be “against the light”, that is, sit with his back to the window.
- A book for checking the color perception of drivers with tables from the patient’s eyes should be 1 meter away, and the tables themselves should be strictly vertical.
- The time allowed to view one image is no more than 7 seconds.
Diagnostic Results
Verification of color perception for drivers can reveal a weakening of the perception of one of the colors (green or red), called abnormal trichromasia, which is divided into three types:
- Complete loss of perception of red or green colors corresponds to type A.
- Significant violation of color perception - type B.
- A slight decrease in color perception by the patient is characterized by type C.
In addition to abnormal trichromasia, Rabkin's polychromatic tables can reveal more rare types of deviations in the patient: dichromasia (non-perception of one of the three colors), as well as monochromasia (when the subject is unable to distinguish two colors at the same time).
Color Impaired Treatment
Testing color perception for drivers can detect both congenital and acquired color blindness. If we are talking about congenital pathology, then, unfortunately, science does not yet know the methods of treatment of this dysfunction of the retina. The only way for color blind people to see the world as it is, in full glory is only the development of Western scientists - special contact lenses. In addition, genetics do not lose hope in developing a special technology that allows the introduction of missing genes responsible for color perception into retinal cells. Perhaps someday the efforts of scientists will bear fruit, and the term "color blindness" will remain in the distant past.
As for the acquired inability to distinguish colors, when assessing the possibility of its cure, the causes of this deviation should be considered.
- Color blindness resulting from age-related changes in the eye cannot be cured. However, science knows cases where replacing the lens returns normal color perception.
- A color perception disorder caused by any chemical drug can be completely cured - you just need to cancel these drugs.
- In case of a violation of color perception caused by any trauma, the outcome will depend on the degree of damage to the retina. In some cases, a complete recovery of perception to its normal value is possible.
Is it possible to "bypass" the test of vision for color sensation
Unfortunately, if the patient suffers from a violation of color perception, then it is almost impossible to pass a test for checking color perception successfully. The option to memorize tables is rather doubtful, since the doctor can give the subject pictures selectively or in a different order. The only way out is to "negotiate" with the doctor. But in this case, you need to understand the seriousness of this act, because life and health of not only yours, but also those of others may depend on this in the future. If you find it difficult even to change a traffic signal, you need to think about whether it is worth the risk.
