………………. acts as diaphragm of eye.

Explanation

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks which part of the eye acts as the diaphragm of the eye.

2. **Understand the Function of the Diaphragm**: In a camera, the diaphragm controls the amount of light that enters the camera. Similarly, in the eye, there is a part that regulates the amount of light entering.

3. **Identify the Relevant Part of the Eye**: The part of the eye that functions similarly to a camera diaphragm is the iris.

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