Question
Describe and explain, how a normal eye can see objects lying at various distances clearly.
✓
Answer
To focus on distant objects, the ciliary muscles of the eye get fully relaxed and pull the suspensory ligaments attached to the eye-lens tightly. This, in turn, stretches the eye-lens and the eye-lens becomes thin. This thin eye-lens has large focal length and small converging power sufficient to converge the parallel rays of light coming from a distant object to form an image on the retina.
To focus on nearby objects, the ciliary muscles of the eyes contract and make the suspensory ligaments loose. The ligaments then stop pulling the eye-lens. The eye-lens bulges under its own elasticity and becomes thick. This thick eye-lens has small focal length and large converging power which converges the diverging rays coming from the nearby object to form an image on the retina.
To focus on nearby objects, the ciliary muscles of the eyes contract and make the suspensory ligaments loose. The ligaments then stop pulling the eye-lens. The eye-lens bulges under its own elasticity and becomes thick. This thick eye-lens has small focal length and large converging power which converges the diverging rays coming from the nearby object to form an image on the retina.
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