An 85 year old male reports to the nurse practitioner that h…

An 85 year old male reports to the nurse practitioner that he is “having trouble with his eyes”.  He reports his color perception has changed as well as he just doesn’t seem to be able to see as well as before.  He has a 30 pack year tobacco history, asthma with at least one episode each year requiring a prednisone burst  and type 2 diabetes with last A1C 7.2.  The nurse practitioner considers the most probable diagnosis based on his past medical history and symptoms as: