Is this a sign of multiple sclerosis?

Last updated at 09:36 02 February 2005

Optic neuritis is in inflammation of the optic nerve, the nerve that takes messages from the eye to the brain. It usually affects just one eye but can affect both, and causes painful loss of vision.

It's a condition that is more common in young adults aged 20 to 49 and usually lasts about one to two weeks, with a gradual recovery over the next three to four weeks.

Optic neuritis can be the first sign of multiple sclerosis, and research has shown that between 50 and 80% of people with optic neuritis have small scars or lesions in the nerve tissue in the brain that they are unaware of.

About 80% of those with these lesions do go on to develop MS - but that means that there are a substantial number of people who have had optic neuritis who don't get MS.