Dalton bought his mother a pair of socks as a birthday present at the age of 28. Mom was surprised: "How can I wear cherry red socks at my age?" Dalton didn't believe it and argued, "This is obviously a pair of gray socks!" " Later, others said that socks were cherry red, and Dalton believed that he was wrong. He feels very strange: why does he look gray and others say he is red? He pointed to his coat and asked others what color it was. He was told it was green, but he always thought it was dark red. His brother is also blind.
Dalton was confused. So, he put down the experiment, carefully studied this strange physiological phenomenon and found the phenomenon of color blindness. Dalton's discovery attracted everyone's attention and people generally consulted it. It turns out that many people are color blind, which proves that color blindness is actually a common physiological phenomenon. For this reason, he wrote a paper "On Public Blindness" and became the first person in the world to raise the issue of color blindness. Later, people called color blindness Dalton's disease in memory of him.
Question 2: What is color blindness? Color blindness refers to the lack of color vision or insufficient color vision, which can be divided into congenital and acquired. For acquired color blindness, you can take Liu's decoction to supplement nutrition and improve the eye condition.
Question 3: What is color blindness?
Color blindness is a visual defect. Because of the abnormal or incomplete photosensitive pigment in cone cells of retina, it lacks the ability to distinguish one or several colors.
Question 4: How to cause color blindness? What causes color blindness? Congenital color vision disorder is usually called color blindness, which can not distinguish various colors or a certain color in the natural spectrum; Those with poor ability to distinguish colors are called weak colors and weak colors; Although people can see the colors seen by normal people, their ability to recognize colors is slow or poor. When the light is dark, some people are almost as tired as color blindness or perform well. It is generally difficult to distinguish strictly, but the severity is different. Congenital factors are common in color blindness and color weakness. What causes color blindness? Because the patient has no normal color discrimination ability since childhood, it is not easy to be found. It is generally believed that red-green color blindness is determined by two pairs of genes on the X chromosome, namely the red-blind gene and the green-blind gene. Because these two pairs of genes are closely connected on the X chromosome, they are often represented by a gene symbol. What causes color blindness? The genetic mode of red-green color blindness is X-linked recessive inheritance. Men only have one X chromosome, so they only need one color blindness gene to show color blindness. Women have two X chromosomes, so they need a pair of pathogenic alleles to behave abnormally. If a normal woman marries a color-blind man, the father's color-blind gene can be passed on to their daughter through the X chromosome, but not to their son. Daughters pass color blindness genes from father to son, which is called cross inheritance. So there are far more male patients than female patients. The corresponding pathological organ is the eye, specifically the retina, specifically the cone cells. Cone cell: the cell shape is similar to that of rod cell. Cone cells are located in the lateral part of the outer nuclear layer, with large nuclei and shallow staining. The cone is also divided into inner and outer parts. Most of the outer membrane discs do not separate from the cell membrane, and the top membrane disc does not fall off. The membrane disc is embedded with visual pigment that can feel strong light and color vision, which is continuously synthesized and supplemented by the inner segment. Humans and most mammals have three kinds of cone cells, namely red sensitive pigment and blue; Blue-sensitive pigment and green-sensitive pigment, if lacking cone cells sensitive to red light (or green light), can not distinguish red (or green) color, and are red (or green) color blindness. The end of the inner process of cone cells expands into a foot, which can form synapses with dendrites of one or more bipolar cells and horizontal cells. Through the above introduction to color blindness, I believe you should have a certain understanding of what causes color blindness. Want to know more about color blindness, click online expert consultation.
Question 5: Briefly describe the causes of color blindness in psychology.
Question 6: Is color blindness caused by natural or acquired factors? Of course, I will also be led astray by some butterflies and regard some praise as spring. I have lost my enthusiasm for me and your indifference.
Question 7: The cause of red-green color blindness is 1. The red-green color blindness gene that determines the disease is recessive and located on the X chromosome.
The male patient gene is Xby, the female patient genotype is xXBXbxb, and the female genotype is x (superscript) bxb.
Therefore, if a male patient marries a normal woman, his sons are normal and his daughters are carriers.
If a female color-blind patient marries a normal man, her sons are all patients and her daughter is the carrier.
If a female color-blind carrier marries a normal male, there will be 1/2' s son and 1/2' s daughter as carriers.
If a female color-blind carrier marries a male color-blind patient, her son 1/2 and daughter 1/2 may get sick, and 1/2 is the carrier.
Red blindness is one of the most common partial color blindness, which can be divided into red blindness and green blindness
People who are blind in red and green can't tell red from green. They regard the whole spectrum as two basic colors: long wave (red, orange, yellow and green) is yellow, and short wave (cyan, blue and purple) is blue.
K.E.Koenig believes that people who are red-green color-blind lack cone cells that feel red or green light.
A.Fick believes that patients' retinas also have two kinds of pyramidal cells that normal people feel red light and green light, but the information sent by these two cells is mixed, so the brain can't tell whether it is red light or green light.
The reason of red-green color blindness is that it can't distinguish red from green, which is a congenital color vision disorder.
The causes of red-green color blindness The genes that control red-green color blindness are located on the X chromosome and are recessive genes, usually expressed by Xb. Because the Y chromosome is too short and lacks homologous fragments corresponding to the X chromosome, there is no gene to control color blindness.
Causes of red-green color blindness If a female homozygote with normal color vision marries a male red-green color blindness patient, in their offspring, the son's color vision is normal; Daughters are normal, but because they got a red-green color blindness gene from their father, they are all red-green color blindness gene carriers.
If a female red-green color-blind gene carrier marries a male with normal color vision, her son 1/2 is normal and 1/2 is red-green color-blind; None of the daughters are color blind, but 1/2 is a color blind gene carrier. In this case, the son's color blindness is inherited from his mother.
The female red-green color-blind gene carrier married the male red-green color-blind patient, and among their offspring, 1/2 was normal, 1/2 was red-green color-blind; My daughter has 1/2 color blindness, and 1/2 is the carrier of color blindness gene.
If a female red-green color-blind person marries a male with normal color vision, their sons are all red-green color-blind in their offspring; Daughters are all normal, but because they got the red-green color blindness gene from their mothers, they are all carriers of the red-green color blindness gene.
Through the analysis of the above four marriage methods, we can see that the male red-green color blindness gene can only be inherited from the mother and then passed on to the daughter. This genetic feature is called cross inheritance in genetics.
Question 8: What are the causes of color blindness and color weakness? Color blindness and color weakness are collectively called color vision disorders, which are divided into two categories: congenital and acquired. Congenital color blindness or color weakness is a hereditary disease, which is related to gender. A few color vision abnormalities are also found in acquired people, such as some fundus diseases and glaucoma. The degree of color vision disturbance caused by these eye diseases is relatively light and disappears with the recovery of primary eye diseases, so most of them have not attracted the attention of patients.