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 condition affecting the lens of the eye, leading to a change in its refractive power. Presbyopia is a common age-related condition where the lens loses its ability to focus on close objects, typically occurring after the age of 40.
**Why the Correct Answer is Right**
The patient's complaints of decreased distance vision, combined with the absence of near vision problems, are classic signs of presbyopia. This condition is caused by the gradual loss of elasticity in the lens, making it difficult for the lens to change shape and focus on close objects. The loss of accommodative ability is due to the decrease in the number of lens fibers and the reduction in the amount of water and proteoglycans in the lens.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not directly related to the patient's symptoms. Myopia (nearsightedness) typically causes difficulty with distance vision, not near vision.
**Option B:** Hyperopia (farsightedness) can cause difficulty with near vision, but the patient's near vision has actually improved, making this option incorrect.
**Option C:** Cataract is a condition where the lens becomes cloudy, leading to vision problems. However, the patient's symptoms suggest a change in refractive power, not a change in lens clarity.
**Clinical Pearl / High-Yield Fact**
Presbyopia is a normal age-related condition that affects the lens's ability to focus on close objects. It typically occurs after the age of 40 and is not a disease, but rather a natural part of aging.
**Correct Answer: D. Presbyopia**