In old age, the vision of eye becomes dim. It is due to

Options

A. Myopia
B. Hypermetropia
C. Cataract
D. Astigmatism.

Answer

### Step-by-Step Solution:

1. **Understanding the Problem**: The question asks why vision becomes dim in old age. This indicates that we need to identify age-related conditions affecting vision.

2. **Identifying Possible Conditions**:
- **Myopia (Nearsightedness)**: This condition allows individuals to see nearby objects clearly while distant objects appear blurry. It is not typically associated with aging.
- **Hypermetropia (Farsightedness)**: In this condition, distant objects are seen clearly, but nearby objects appear blurry. While it can occur with age, it is not the primary cause of dim vision in older adults.
- **Cataract**: This condition involves clouding of the lens in the eye, leading to blurry vision and is commonly associated with aging.
- **Astigmatism**: This is a refractive error caused by an irregular shape of the cornea or lens, leading to blurred vision. It can occur at any age and is not specifically related to aging.

3. **Analyzing Each Condition**:
- **Myopia**: Not relevant to old age.
- **Hypermetropia**: While it can occur with age, it is not the main cause of dim vision in older adults.
- **Cataract**: This is a common condition in older adults characterized by clouding of the lens, leading to dim vision.
- **Astigmatism**: Not specifically related to aging.

4. **Conclusion**: The primary reason for dim vision in old age is cataract, due to the clouding of the lens in the eye.

5. **Final Answer**: The vision of the eye becomes dim in old age primarily due to cataract.