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The muiscles of a normal eye are least s...

The muiscles of a normal eye are least strained when the eye is focussed on an object

A

far away from the eyes

B

very close to the eye

C

at abot 25 cm from the eye

D

at about 1 m from the eye

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The correct Answer is:
To solve the question regarding the strain on the muscles of a normal eye when focused on an object, we can follow these steps: ### Step 1: Understanding Eye Muscles The eye has muscles that control the shape of the lens. These muscles are responsible for adjusting the focal length of the lens to focus on objects at different distances. ### Step 2: Identifying Object Distances The question provides four options regarding the distance of the object from the eye: 1. Far away from the eyes 2. Very close to the eye 3. At about 25 cm from the eye 4. At about 1 m from the eye ### Step 3: Analyzing Muscle Strain - When an object is **far away**, the light rays entering the eye are nearly parallel. In this case, the ciliary muscles relax, and the lens flattens, requiring minimal effort to focus. - When an object is **very close**, the ciliary muscles contract to make the lens thicker, which increases the strain on the muscles. - At a distance of **25 cm**, the eye still needs to exert some effort to focus, as this is relatively close. - At a distance of **1 m**, the strain is less than when focusing on something very close, but it is still more than when focusing on something far away. ### Step 4: Conclusion The least strain on the eye muscles occurs when the eye is focused on an object that is **far away**. This is because the muscles are relaxed, and there is no need for significant adjustment of the lens. ### Final Answer The muscles of a normal eye are least strained when the eye is focused on an object **far away from the eyes**. ---
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