@haj
A number of seizure medications have visual side effects, some have actually caused blindness. Probably most notable is Sabril. I took gabapentin too but it wasn't effective for my neuropathy or seizures. Exactly why gabapentin causes visual problems isn't fully known.
You might want to be checked out by an ophthalmologist just to set your mind at ease. I have taken anticonvulsants for nearly 60 years now.
Jake