The treatments of optic neuritis are various, and the appropriate therapy is determined by the causes. The causes related to multiple sclerosis needs about 12 weeks to return to normal. While, if your optic neuritis is caused by infection or other disease, the time of treatment could be longer. The only way for you recover more quickly should be following the doctor's suggestion.
If you have the optic neuritis and do some medical things to recover from it, you will get the basic recovery after about two weeks. You should not eat the spicy food. Instead, you should eat some food with vitamin C. You could also use warm compress which could treat your optic neuritis quickly.