If it's optic neuritis, my eye doctor has told me that the pain only usually lasts about a week, and the pain is variable. I had good luck taking prescription migraine medication when it hurt really bad.

Sometimes going into places with certain types of light (grocery stores with fluorescent light) made things worse for me...it would trigger optic nerve pain.

Staying in dim light, or if you have lights on a dimmer switch, turning the light down to where it's comfortable but you can still see to get around might help the pain. TV made my eyes hurt too.