neurological vision problems

if visual problems are symmetrical and completely identical in your eyes is the cause neurological? I have blind spots developing in both eyes that are completely identical and happen at the exact time in both eyes. I've seen 2 retina specialist and after every eye exam under the sun, nothing but "everything appears text book healthy". So I'm starting to rule out my eyes as the cause, no family history, I'm 27 and an erg,mferg and vep showed nothing. Both doctors said that even if I had a degenerative eye disease, these test would have picked them up before any visual problems manifested. But I find it interesting/scary that it affects both eyes the same, I know its bizarre. I had a normal mri but I also know that a neurologist can perform other test. I also have migraine with aura. This sounds like its a brain thing. My question: what part of the body would cause symmetrical visual disturbances? Thanks hope to hear from you soon