A 55 year old patient complains of decreased distance vision. However, now he does not require his near glasses for near work. The most likely cause is-
**Core Concept**
The patient's symptoms suggest a change in the refractive status, likely due to an age-related condition affecting the lens or the cornea. Presbyopia is a common condition characterized by difficulty with near vision, typically requiring corrective lenses for near work.
**Why the Correct Answer is Right**
The patient's symptoms are consistent with presbyopia, a condition caused by the aging of the lens. The lens becomes less flexible with age, making it difficult to focus on near objects. This is due to the decrease in the ability of the lens to change its shape (accommodation) and the increase in the refractive power of the lens. The presbyopic patient can see distant objects clearly but requires corrective lenses for near vision. The fact that the patient no longer requires near glasses for near work suggests that the presbyopia is being compensated for by another factor, possibly the development of hyperopia (farsightedness).
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not relevant to the patient's symptoms and would not explain the change in refractive status.
* **Option B:** This option is not a common cause of decreased distance vision and would not explain the patient's symptoms.
* **Option C:** This option is a common cause of decreased distance vision, but it would not explain why the patient no longer requires near glasses for near work.
**Clinical Pearl / High-Yield Fact**
Presbyopia is a natural age-related condition that affects the lens and is a common cause of difficulty with near vision in middle-aged patients. It can be compensated for with corrective lenses, such as reading glasses, or with surgical interventions.
**Correct Answer:** C. Presbyopia