Hi Carolyn,
I think diabetes could be the culprit.
My eyesight is a bit worse now after my annual ophthalmology test and I've gone from being pre diabetic to diabetic.
I could probably google impaired eyesight for PWP and find a few hits but I've had P.D. a long time and blame my lack of insight into the world of type 2 diabetes and its consequences.
Am now taking steps to prevent further progression of diabetes and hopefully my eyesight won't get much worse in future.
I'd hate not being able to read!
Best wishes