abnormal color vision
Introduction
Introduction Color vision is a fundamental and important component of visual function and is a special sensory function of human retinal cone cells. The normal human visual function recognizes visible light with a wavelength of 380-760 um, and is composed of purple, blue, cyan, green, yellow, orange, and red. Color vision disorders include color blindness and color weakness. Color blindness means that the color discrimination ability disappears, and the color weakness means that the color recognition ability is lowered. People with abnormal color vision are limited in their career choices. Such as transportation, smelting, fine arts, chemicals, weaving and dyeing, medicine, etc., must have a normal color perception. Therefore, color vision examination has been used as a routine item of physical examination.
Cause
Cause
Color vision disorders include color blindness and color weakness. Color blindness means that the color discrimination ability disappears, and the color weakness means that the color recognition ability is lowered. People with abnormal color vision are limited in their career choices. Such as transportation, smelting, fine arts, chemicals, weaving and dyeing, medicine, etc., must have a normal color perception. Therefore, color vision examination has been used as a routine item of physical examination.
Examine
an examination
Related inspection
Nagel color vision examination method
(1) medical history
Generally, congenital color blindness has many symptoms, which are usually found during routine color vision examination in physical examination. Due to genetic factors, you should ask about family history in detail. If the patient complains of visual impairment, and has a history of lesions such as the retina, optic nerve or lower occipital cortex, attention should be paid to color vision examination, often with color vision abnormalities.
(2) Physical examination
Systemic examinations must be taken to exclude certain systemic lesions that can cause acquired color vision abnormalities. For example, neurological examination can exclude occipital cortical lesions.
Eye examination should pay attention to routine examinations such as vision, pupil, fundus, and visual field. In particular, fundus examination, to understand the retinal, optic nerve, macular lesions, to help diagnose the secondary color vision abnormalities.
There are many methods for color vision examination, but they are all subjective inspection methods.
False color map
Often referred to as color blindness. It is currently the most widely used inspection method. It uses patterns of colors, letters, letters, or curves that are confusing with the same shades of color. Normal people are identified by color, while those with color blindness are judged by light and dark. There are the Ishilara color blind checklist from Japan, and the Hardy-Rand-Ritter (HRR) watch from the United States. The domestic use of Yu Ziping color blind inspection map.
2. Colored velvet group selection method
In a pile of woolen yarns mixed with various colors, the examinee picks a similar color from a certain color. If you can't choose a similar color, it is an abnormal color vision.
3.FM-100 color test
The 85 movable hue sub-boxes of 4 boxes will be arranged under fixed illumination and arranged according to the color change, each box is limited to 2 minutes. Record the number on the back of the hue on the score sheet, draw the polarity map, and compare it with the semicolon on the recording paper, and count the total error score, which can be used for color vision abnormal classification and quantitative analysis.
4. Color vision mirror
Using the principle of proper mixing of red and green light into yellow light, the amount required for red-green light matching is recorded to judge the red-green sensation. This method is simple and can check for excellent blindness or color weakness. Can be quantitative, easy for clinical observation and scientific research applications.
5.D-15 color wheel test
It consists of two groups of 15 hue sub-groups, and the order of the records is recorded. The curve is drawn according to the chart requirements to judge the color vision abnormality.
(three) device inspection
In order to clarify the detailed diagnosis of optic nerve, retina and macular degeneration, fundus fluorescein angiography and electrophysiological examination are feasible. It is also possible to further identify intracranial lesions causing color vision disorders by CT scanning or the like.
Diagnosis
Differential diagnosis
It should be differentiated from the following symptoms:
Congenital color vision disorder
Mostly recessive inheritance, that is, a color-blind male passes the genetic (X chromosome) through his daughter to the grandson (male) generation. The incidence of color vision disorder was 5.14% for men and 0.73% for women. Mostly for both eyes. In addition to full color blindness, there is usually normal retinal function. Generally only red and green are involved.
2. Acquired color vision disorder
It can be caused by diseases of the macula, retina, optic nerve and occipital cortex. It can be a single eye, and the degree of involvement of both eyes can be different. There are many abnormalities in visual function, which often affect yellow-blue and red-green. Retinopathy is dominated by blue-yellow disorders. Optic neuropathy is dominated by red and green obstacles. Such as retinitis pigmentosa. Retinal detachment, vasospasm retinopathy, and age-related macular degeneration can cause blue color vision abnormalities.
