When a person is looking at objects kept at different distances then which one of the following factors remains constant ?

Options

A. power of eye lens
B. distance of object from eye lens
C. distance of image from eye lens
D. radius of curvature of eye lens

Explanation

To solve the question "When a person is looking at objects kept at different distances, which one of the following factors remains constant?", we can analyze the options provided and understand the functioning of the human eye.

### Step-by-Step Solution:

1. **Understanding the Eye's Functionality**:
- The human eye functions similarly to a camera. It has a lens (the eye lens) that focuses light onto the retina, which is the image sensor of the eye.

2. **Identifying the Factors**:
- The question provides several factors to consider:
- Power of the eye lens
- Distance of the object from the eye lens
- Distance of the image from the eye lens
- Radius of curvature of the eye lens

3. **Analyzing Each Factor**:
- **Power of the Eye Lens**:
- The power of the lens changes when the eye focuses on objects at different distances. Therefore, this factor is not constant.

- **Distance of the Object from the Eye Lens**:
- As the person looks at objects at varying distances, this distance will obviously change. Thus, this factor is also not constant.

- **Distance of the Image from the Eye Lens**:
- The distance from the eye lens to the retina (where the image is formed) remains constant because the size of the eyeball does not change. This factor is constant.

- **Radius of Curvature of the Eye Lens**:
- The curvature of the eye lens can change depending on the focusing needs of the eye (for near or far objects). Hence, this factor is not constant.

4. **Conclusion**:
- The only factor that remains constant when a person looks at objects at different distances is the **Distance of the Image from the Eye Lens**.

### Final Answer:
The factor that remains constant is the **Distance of the Image from the Eye Lens**.

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