Question
Question: Assertion:The eye is said to have the power of accommodation. Reason:Ciliary muscles alter the sha...
Assertion:The eye is said to have the power of accommodation.
Reason:Ciliary muscles alter the shape of the lens for near or far vision during accommodation.
(A)Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
(B)Both Assertion and Reason are correct But Reason is not the correct explanation for Assertion
(C)Assertion is correct but Reason is incorrect
(D)Both Assertion and Reason are incorrect
Solution
The ability to focus the eye on nearby as well as distant objects is called the power of accommodation of the eye.In healthy eye power of accommodation is approx 4 diopters.
Complete answer:
Let’s discuss the options and find out the correct answer
The choroid is the middle layer of the eyeball which is connected in front to a thick structure called the ciliary body. Suspensory ligaments which are thread like structure extend from the ciliary body and get attached to a biconvex which is transparent elastic Lens. For proper vision, the light rays from a visual object must be focussed correctly and precisely on the retina. The lens in this resting eye focuses parallel rays from distant objects (more than 6 m away) on the retina. But to increase the power of the lens for focusing divergent rays from objects on the retina. A reflex called accomodation is needed. The eye has a very beautiful property which is to form an image of both near and far objects on the retina by changing the convexity of the lens. That is known as the power of accommodation.
Hence, the option C : 'Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion'.
Note: The process by which certain muscles (called ciliary muscles) function, to change the focal length of the eyes so that the image is clearly formed on the retina is called the accommodation of the eye.