People with optic neuritis may have symptoms such as blurry vision, distorted vision, decreased color vision, blind spots and will potentially suffer vision loss. In addition, it is estimated that about 92% of optic neuritis patients feel pain in the eye, which sometimes precedes the appearance of vision loss. Underlying changes caused by optic neuritis can be abnormal pupil appearance. The pupil performs abnormally that it will dilate instead of constricting in the presence of bright light. And the optic nerve may appear normal or swollen.