write the functions of each of the following parts of the human eye:corena,iris,crystalline(eye) lens,cillary muscles,pupil
Answers
cornea: The cornea acts as the eye's outermost lens. It functions like a window that controls and focuses the entry of light into the eye
iris: In humans and most mammals and birds, the iris (plural: irides or irises) is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina.
eye lens: The lens is located in the eye. By changing its shape, the lens changes the focal distance of the eye. In other words, it focuses the light rays that pass through it (and onto the retina) in order to create clear images of objects that are positioned at various distances.
ciliary muscles: The main function of the ciliary muscles used to change the shape of the lens in the eye to help with focusing. Another function of the ciliary muscles is to help regulate the flow of aqueous humor in the eye
pupil: The whole job of the iris and pupil is to control the amount of light that gets into the eye.
Answer:
The cornea shares this protective task with the eyelids, the eye socket, tears, and the sclera, or white part of the eye. The cornea acts as the eye's outermost lens.
circular structure in the eye, responsible for controlling the diameter and size of the pupil and thus the amount of light reaching the retina. Eye color is defined by that of the iris.
The lens, by changing shape, functions to change the focal distance of the eye so that it can focus on objects at various distances, thus allowing a sharp real image of the object of interest to be formed on the retina.
The iris contracts and dilates involuntarily and changes the size of the pupil. The whole job of the iris and pupil is to control the amount of light that gets into the eye. It's called a pupillary reflex, and you have probably noticed that a person's pupils are smaller in bright light and bigger in low light.
Ciliary muscle: A circular muscle that relaxes or tightens the zonules to enable the lens to change shape for focusing. The zonules are fibers that hold the lens suspended in position and enable it to change shape during accommodation.
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