In presbyopia

Options

A. The eye ball becomes short
B. The lens become opaque
C. The retina gets damaged
D. Diminution of accommodation of lens due to loss of elasticity

Answer

### Step-by-Step Solution:

1. **Understanding Presbyopia**:
- Presbyopia is a vision defect that typically occurs in older adults. It is characterized by the inability to focus on near objects as well as far objects.

2. **Cause of Presbyopia**:
- The primary cause of presbyopia is the loss of elasticity in the lens of the eye. As people age, the lens becomes less flexible, making it difficult to change its shape for focusing on objects at different distances.

3. **Effect on Ciliary Muscles**:
- The decrease in lens elasticity affects the contraction of the ciliary muscles, which are responsible for adjusting the shape of the lens. This leads to a reduced ability to accommodate, or focus, on objects that are near.

4. **Understanding Accommodation**:
- Accommodation is the process by which the eye adjusts its focus to see objects clearly at different distances. In presbyopia, this accommodation is diminished due to the loss of lens elasticity.

5. **Evaluating the Options**:
- **Option 1**: "The eyeball becomes short" - This is incorrect as it relates to conditions like hypermetropia.
- **Option 2**: "The lens becomes opaque" - This describes cataracts, not presbyopia.
- **Option 3**: "The retina gets damaged" - This is unrelated to presbyopia and could occur due to other injuries or disorders.
- **Option 4**: "Diminution of accommodation of lens due to loss of elasticity" - This is the correct answer as it directly relates to the cause of presbyopia.

6. **Conclusion**:
- The correct answer to the question regarding presbyopia is the fourth option: "Diminution of accommodation of lens due to loss of elasticity."