Optic Neuritis

In this illustration, the images in the left column show a healthy optic nerve and healthy myelin sheaths.

The images in the right column show an inflamed optic nerve and damaged myelin.

The bottom line graphics show visual evoked potentials (VEP). A VEP measures how quickly and strongly visual signals travel from the eye to the brain. In optic neuritis, these signals are usually slower, and in some cases weaker.