Im a 32 yr old female with ms. i again have eye pain and eye movement is also painful. how do i know this is not an onset of optic neuritis.?

MAYBE: As you already know, eye pain with movement can be associated with optic neuritis, but also you can experience loss of vision and color desaturation. If you are noting difficulty with blurring or focus, and bright reds are pink, this may be the initial manifestations, and this needs to be treated asap. Even if other cause for your symptoms, contact your neurologist and have this checked.

Could be: If you have had a change in vision in either eye it could indeed be optic neuritis. See an eye doctor immediately if you experience a decrease in vision in either eye.