Weak blue-yellow

Introduction The difference in color discrimination is called weak color, and the boundary between it and color blindness is generally not easy to distinguish strictly, but the degree of severity is different. Color weakness includes weak color and partial color weakness (red weak, green weak, blue-yellow weak, etc.). Blue and yellow are also known as the third color blind. The patient's blue-yellow color is unclear and is identifiable to red and green. Blue-yellow blindness includes blue blind (tritanopia, third color blindness) and blue weak (tritanomaly, third color weak). Blue-yellow blindness is one of color blindness. Since the patient does not have normal color discrimination ability since childhood, it is not easy to be found.

Cause

Since the patient does not have normal color discrimination ability since childhood, it is not easy to be found. It is generally believed that red-green blindness is determined by two pairs of genes on the X chromosome, namely the red blind gene and the green blind gene. Since these two pairs of genes are closely linked on the X chromosome, they are often represented by a gene symbol. The genetic pattern of red-green blindness is X-linked recessive inheritance. Men have only one X chromosome, so they only need a color-blind gene to perform well. Women have two X chromosomes, so they need to have a pair of pathogenic alleles to behave abnormally. If a normal woman marries a color-blind male, the father's color-blind gene can be passed to their daughter along with the X chromosome and cannot be passed on to the son. The daughter passed the color blind gene from her father to her son. This phenomenon is called cross-genesis. Thus there are far more male patients than female patients.

an examination

Related inspection

Color vision pilot physical examination Farnsworth 15 color standard test Nagel color vision examination FM-100 color test

Color blind (weak) patients are born with no correct color discrimination ability, and think that others are the same as themselves, so they can not be consciously sick, and many color blind patients have no abnormal findings in eye examination. How to determine color blindness and color weakness? Color blindness and color weakness are mostly checked by subjective inspection, generally in brighter natural light. The commonly used inspection methods are as follows.

False homochromatic map: commonly referred to as a color-blind book, which uses dots of the same shade and different colors to form numbers or figures, and reads at a distance of 0.5 m under natural light. The color blindness should be corrected when checking, and each figure should not exceed 5 seconds. Color vision disorders are difficult to identify, misread or impossible to read, and can be confirmed according to the color blindness table.

Color Harness Test: It is a mixture of different shades of yarns of different colors, so that the examinee picks out the same color bundle as the standard harness. This method is quite time consuming and can only be qualitatively and cannot be quantified, and is not suitable for large-area screening tests. Color Mixing Tester: It is a kind of spectrometer designed by nagel based on the principle of red + green = yellow. It can quantitatively record the amount of red and green light matching to determine the red and green anomaly. This method can be qualitative. It can be quantified.

Differential diagnosis

Differential diagnosis of blue and yellow:

Blue and yellow blind: blue and yellow blind, also known as the third color blind. The patient's blue-yellow color is unclear and is identifiable to red and green. People with blue-yellow color blindness are difficult to recognize blue and yellow. Blue-yellow blindness includes blue blind (tritanopia, third color blindness) and blue weak (tritanomaly, third color weak). Blue-yellow blindness is one of color blindness.

Color blind (weak) patients are born with no correct color discrimination ability, and think that others are the same as themselves, so they can not be consciously sick, and many color blind patients have no abnormal findings in eye examination.

How to determine color blindness and color weakness? Color blindness and color weakness are mostly checked by subjective inspection, generally in brighter natural light. The commonly used inspection methods are as follows.

False homochromatic map: commonly referred to as a color-blind book, which uses dots of the same shade and different colors to form numbers or figures, and reads at a distance of 0.5 m under natural light. The color blindness should be corrected when checking, and each figure should not exceed 5 seconds. Color vision disorders are difficult to identify, misread or impossible to read, and can be confirmed according to the color blindness table.

Color Harness Test: It is a mixture of different shades of yarns of different colors, so that the examinee picks out the same color bundle as the standard harness. This method is quite time consuming and can only be qualitatively and cannot be quantified, and is not suitable for large-area screening tests. Color Mixing Tester: It is a kind of spectrometer designed by nagel based on the principle of red + green = yellow. It can quantitatively record the amount of red and green light matching to determine the red and green anomaly. This method can be qualitative. It can be quantified.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.