write the function of ciliary muscles and optic nerves and rods and cones
Answers
Answer:
Ciliary muscles : 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.
Optic Nerve : The optic nerve is located in the back of the eye. It is also called the second cranial nerve or cranial nerve II. It is the second of several pairs of cranial nerves. The job of the optic nerve is to transfer visual information from the retina to the vision centers of the brain via electrical impulses
Rods & Cones : Rods are responsible for vision at low light levels (scotopic vision). They do not mediate color vision, and have a low spatial acuity. Cones are active at higher light levels (photopic vision), are capable of color vision and are responsible for high spatial acuity. The central fovea is populated exclusively by cones.
Answer:
Ciliary Muscles adjust the size of crystalline lens, hence adjust the amount of light entering in eye. It also focus light in Retina to obtain sharp image of the object .
Optic nerve transferS visual information from the retina to the vision centers of the brain via electrical impulses. There it is perceived as a image and the image in set in our mind
Rods are light sensitive cells (photoreceptor cells) in the retina of the eye.
They are usually found concentrated at the outer edges of the retina
They have rod-like structure
They provide twilight vision (peripheral vision).
They are more sensitive to light than cones
Cones are light sensitive cells (photoreceptor cells) in the retina of the eye.
They are usually found concentrated at the Center of the retina.
They have cone-like shape.
They allow the perception of colour.
They are less sensitive to light than rods .