Lenses used by those who cannot see near objects are

Options

A. Plain
B. Concave
C. Convex
D. Any of the above

Answer

To solve the question about the lenses used by those who cannot see near objects, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Condition**:
- The question refers to individuals who cannot see near objects clearly. This condition is known as **farsightedness** or **hypermetropia**.

2. **Understand the Nature of Farsightedness**:
- In hypermetropia, a person can see distant objects clearly but struggles with nearby objects. This occurs because the image is formed **behind the retina**.

3. **Reason for the Condition**:
- The primary reason for this condition is that the eyeball is often too short, which prevents the eye from focusing on nearby objects.

4. **Corrective Lenses**:
- To correct hypermetropia, a specific type of lens is used. The lens required is a **convex lens**. Convex lenses help to converge light rays before they enter the eye, allowing the image to be focused correctly on the retina.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the lenses used by those who cannot see near objects are **convex lenses**.

### Final Answer:
- The lenses used by those who cannot see near objects are **convex lenses**.

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