This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Frequent changes of reading glasses in a 60yr old male patient is a feature of 
Select and explain. 
A. Primary open angle glaucoma, B. Senile nuclear cataract, C. Acute angle closure glaucoma, D. Presbyopia
A: Primary open angle glaucoma
Answer: A: Primary open angle glaucoma 
Explanation: Frequent changes of reading glasses is a feature of Primary open angle glaucoma.