Dilated pupils are not usually required for optic nerve morphologic examinations, but they are usually required for electrophysiologic examinations of optic nerve function. The optic nerve is an important structure in the eye that brings together the axons of ganglion cells in the retina and then transmits them via the optic nerve to the visual center of the brain to form vision. The optic nerve examination is usually performed without dilating the pupils, and the optic nerve can be examined directly for abnormalities in its morphology by using a funduscope or funduscope color film under a small pupil. The function of the optic nerve can also be examined, such as visual evoked potentials examination, which generally does not require dilation and can be completed with a small pupil. However, electrophysiologic examinations generally require pupil dilation. It is recommended that patients with optic neuropathy seek prompt medical attention to evaluate their condition and select the appropriate treatment as prescribed by their doctor.