Structure and functions of each part of the eye
The human eye is the most sensitive and incredible sense organ among all sense organs because with its help we become able to see beautiful and wonderful colors of the world. We can identify the objects around us to some extent by touch, smell, and sound. It is, however, impossible to detect colors while closing the eyes. The structure of the human eye is almost spherical in shape with a diameter of 2.3 cm. The human eye is just like a camera, its lens system also projects the images on a screen called the retina just like a camera. Here in this post, we have presented a post-human eye-structure and functions of each part which will help you answer each question related to the structure and functions of the human eye. The human eye is made of three chambers, the first chamber is between cornea and iris which is filled with aqueous humor, the second chamber is between iris and crystalline lens and the third chamber is between the crystalline lens and retina which is filled with vitreous humor. Its two main lenses are the cornea and crystalline lens which refracts light rays and focus to the retina where the inverted image is formed, at the exit of the eye the optic nerve gets the signal of the inverted image, this signal transported to the brain than brain deciphers this inverted image to erected image. At the end of the post ‘Human Eye – Structure and functions of each part’ please don’t forget to write your comment that how did you like our this post “Human eye-Structure and function of each part”.
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Human Eye, Structure & Functions
In the structure of the eye, the cornea has a very important role. the cornea is a 5 layered transparent vascular tissue made of collagens and cells, it is the outermost lens of the eye and bulged in shape, light rays, first of all, fall on it and then refracted into the eye. The 65 to 75 % of the total refraction of the light takes place through it.
Aqueous humor is a transparent fluid between cornea and iris and between iris and lens, it is composed of water vitamins, sugars, proteins, and other nutrients. The role of aqueous humor. is to nourish cornea and lense because both of them does not contain blood vessel. The aqueous humor maintains the intraocular pressure of the eye and protects the eye from the dust, pollen grains, wind, and microbes.
The colored part of the eye is known as iris, it is located between the cornea and crystalline lens. Iris is made of the dark muscular diaphragm made of connective tissue and muscle covered with pigments responsible for the color of the eye, it surrounds the pupil. Iris controls the size of the pupil.
The pupil is actually the aperture of the eye, It is an opening at the center of the iris and circular in shape, the function of pupil is to allow light to enter the eye so it can be focused on the retina. It appears black color because the light focused on the retina is completely absorbed by the retina and is not reflected back.
The Christine lens is basically is an eye lens that is transparent and located behind the iris. It is not having blood vessels so it is nourished by aqueous humor that exists between iris and lens. One-third of the total net refraction of light through the eye is taken place by the Christine lens. it is made of small flexible smooth muscles called ciliary muscles, these muscles change the shape of the lens. When we see nearby objects, these muscles constrict and radius of curvature of the lens decreases so that images could be focused on the retina and when we see the far objects these muscles dilate and radius of curvature of lens increases so that images could be focused on the retina, this action of eye is known as accommodation of eye.
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Vitreous humour is a jelly-like transparent fluid that contains 99% water and it’s 1% is sugar, vitamins, proteins, hyaluronic acids, and collagens. This fluid pressurizes the retina to remain in its place and gives the spherical shape to the eye.
The retina is located at the back end of the eye, it is made of photosensitive cells called photoreceptors, photoreceptors are of two kinds cones and rods. The rods show us images in dim light or when it is dark, cons show us light during the day time or when light is intense, we see colors of the images because of cons.
The images formed in the retina is inverted, the signal of the image is conducted through the optic nerve to the visual cortex of the brain, the image is decoded by the brain and then we see the inverted image as an erected image.