I have gone through a horrific host of painful issues since taking gabapentin for seven weeks at 1200mg-2100mg per day. Lots of physical and psychological problems that haven't let up, and were not present in any capacity prior to taking gabapentin. Things like nerve pain, heart palpitations, exercise intolerance, derealization, irrational fears, inability to drive, nonstop hair loss, etc. It's been horrible, and this seven weeks of gabapentin use was in February - March 2015.
Anyway, I've gone to a bunch of doctors and specialists for it. Neurologists, cardiologist, internist, pain management, psychopharmacologist, etc. You name it. I've gone through a bunch of tests (MRI, CT scan, blood work, etc) and none of these tests have shown that anything is wrong with me. I have blurry vision in my right eye and have undergone several eye exams and it has shown no problem.
So, even if you still have lingering issues from your gabapentin use, it likely won't show up on any tests.