What is power of accommodation of a human eye ?

Explanation

**Step-by-Step Solution:**

1. **Understanding the Human Eye Structure:**
- The human eye consists of a fixed lens and a retina (which acts as a screen). The lens is responsible for focusing light onto the retina to form clear images.

2. **Concept of Focal Length:**
- The focal length of a lens is the distance from the lens to the point where it focuses light. In the human eye, the lens can change its focal length to focus on objects at various distances.

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