I have had optic neuritis and treated it with steroids. Although in
the first few months I had a little vision come back. I am legally
blind in my one eye now. My Neurologist said usually 6 months, but
there are cases that people have gotten there visions back after that. I think
it is just different for everyone.

When I went to my MS specialist she told me in order for MS to be
diagnosed lesions have to appear over time and space. Which
basically means that you have to have more then one MS episode and
your MRI has to show different lesions. Some places are more lax on these
standards though when they are pretty sure of a case because they want to get
their patient on a medicine as soon as possible.

Good Luck to you. I know how truly frustrating it can be.