Optic neuritis is a condition that affects the optic nerve. This nerve carries visual information from the eyes to the brain. Optic neuritis can cause vision problems, including blindness, and may be caused by a number of different things, such as an infection or exposure to chemicals. Some people are more likely to develop optic neuritis than others, and it can often be difficult to tell if someone has it until they start having serious vision problems. There are many different types of drugs that can help treat optic neuritis, but there is no one drug that is always effective.