The shape of eye lens is changed by

Options

A. pupil
B. iris
C. optic nerve
D. ciliary muscle

Explanation

To answer the question "The shape of eye lens is changed by," we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure Involved**: The eye lens is a crucial part of the eye that helps in focusing light onto the retina.

2. **Understand the Mechanism of Change**: The shape of the eye lens changes to focus on objects at different distances. This process is called accommodation.

3. **Locate the Controlling Muscles**: The muscles responsible for changing the shape of the eye lens are located in the ciliary body.

4. **Identify the Type of Muscles**: The ciliary body contains ciliary muscles, which are smooth muscles.

5. **Explain the Function of Ciliary Muscles**: When the ciliary muscles contract, they cause the lens to become thicker for near vision (accommodation). When they relax, the lens becomes thinner for distant vision.

6. **Conclude with the Answer**: Therefore, the shape of the eye lens is changed by the ciliary muscles.

### Final Answer:
The shape of the eye lens is changed by the ciliary muscles.

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