When we see different colors, our eyes can perceive the differences in the different lights that reach our eyes. Just as the ear can recognize the frequencies of different sounds, our eyes can recognize different colors. For example, the keys on the left side of the piano keys emit a low frequency sound, and the keys on the right side of the piano keys have a higher audio frequency than the left side, and we can see different colors in a similar way. The colors of each rainbow always appear in the same order: red, orange, yellow, green, blue, indigo, purple, the colors of the rainbow corresponds to different wavelengths of light. Red light has a longer wavelength and blue light has a shorter wavelength. Just like a piano has different keys, different wavelengths of light correspond to different colors. 1. How does the eye see color? If you compare the eye to a camera, the anterior segment of the eye includes crystals that focus the image on the retina, which is covered with special nerve cells, including the cone and rod cells. The cone and rod cells contain the optic pigments that produce a response when light hits them. The cone cells are responsible for color vision and contain three types of optic pigments (retinoblue) that are sensitive to red light, blue light, and green light depending on the absorption spectrum, and the three types of pigment cells are stimulated to mix together to form color vision. The optic pole cell contains only one type of optic pigment (retinol), which is sensitive to light and best absorbs blue-green light at 500 nm, and the division of night vision. The eye can recognize a variety of colors when the optic cone cells and the optic rod cells are working together. This is like a painter who can mix several colors to get a variety of colors. 2.What is color blindness? If the cone cells are missing their optic pigment, the eye will not be able to distinguish colors in the normal way. This is called color vision deficiency or color blindness. If only one type of optic pigment is missing, the eye will not be able to recognize a fixed color. Red-green color blindness is when red and green colors look the same and is the most common type of color blindness, followed by blue-yellow color blindness. People with blue-yellow colorblindness usually also have red-green colorblindness. Some people have visual cone cells that do not contain any pigment, so the eye cannot recognize any color and is the most severe form of total color blindness. 3.What causes color blindness? Color blindness is a genetic disorder with a prevalence of 1 in 10 males and a rare occurrence in females. Color blindness is usually caused by the eye’s inability to produce the visual pigments needed for color vision. 4. Can color blindness cause other health problems? Congenital color blindness does not lead to loss of vision or total blindness. However, because the visual cone cells are responsible for fine vision, people with color blindness are unable to obtain good stereo vision. The optic rod cells are often overexposed, so dark glasses can help people with color blindness to get better vision. If you think you have a problem with color vision, you should go to an eye clinic immediately and your doctor will tell you if there are any abnormalities in your color vision and what to do about them.