The human eye is the finest mechanism, the well-coordinated work of its parts is incredibly important for human life. Vision is a complex, not fully understood system of interaction between the eye and the human brain.
Instructions
Step 1
What is the eye The human eye is an optical system. A ray of light, passing through the cornea and pupil (natural diaphragm), is focused by the crystalline lens - a living lens and hits the bottom of the optic cup, where the retina is located. The retina consists of rods, which are light-sensitive cells responsible for human twilight vision, and cones, which are responsible for color perception.
Step 2
The Role of Visual Purple The visual pigment found in rods and cones is called visual purple. When the image, focused by the lens, hits the retina, a photochemical process occurs, which causes the fading of the visual pigment. This is why we see. Simultaneously with fading, the process of creating visual purple occurs. Violation of this process leads to blindness.
Step 3
The Retina-Brain Connection The way the human eye works is often compared to the way a camera works. The image obtained on the retina is of slightly poorer quality than on the film of a professional camera, but we do not notice it. This is because human vision is the interaction of the optical system (eye) and the brain. The brain and the retina itself correct the resulting image, making it perfect.
Step 4
Color vision The process of color perception by the human eye is still poorly understood. Only in the mid-60s of the twentieth century, scientists managed to prove the theory of three-component color vision. It was found that cones are divided according to spectral sensitivity into red-, blue- and green-sensitive. Each cone group contains its own visual pigment.
Step 5
Day and night vision In the center of the retina are mostly cones, the rest of it is occupied by rods. The rods are responsible for colorless human vision due to their sensitivity to light. It has been proven that the retina of the eyes of nocturnal animals (owls, bats) contains practically only rods. Therefore, they see well at night and poorly during the day. The world is black and white for them.
