A good place that I might start is a board certified ophthalmologist. I did a quick search in Indiana and you had a couple of choices. I'd let that person work with a neurologist but I would likely start there if the only issue was the eyes. If there were other neurological issues (falling over, staggering gait, etc), I might go right to neuro. Your vet should be able to help you decide on the type of specialist. Here is the link for Ophthalmologist veterinarians
Search Page
and here is one for neurologists
ACVIM