The cause of optic neuritis may be unknown, but it is thought to be a result of swelling and destruction of the myelin coating of the optic nerve. The inflammation may be the result of a viral infection, or autoimmune diseases such as multiple sclerosis.

• rapid loss of vision in one eye
• loss of color vision
• pain on movement of the eye

• visual acuity
• color vision testing
• viewing the optic disc through dilated pupils
• visual field testing

Visual acuity may return to normal within 2 to 3 weeks with no treatment. Intravenous corticosteroid therapy may accelerate visual recovery, but may be associated with systemic side effects. If visual recovery does not occur, further diagnostic evaluation may be necessary. Occasionally, surgery is indicated to relieve pressure within the optic nerve sheath.

• side effects of therapy
• vision loss

Call your eye doctor if sudden loss of vision in one eye occurs. If you already know you have optic neuritis, call if vision decreases, pain in the eye develops, or if symptoms do not improve with treatment.