The dorsal coloration of the ocellated electric ray is extremely variable, with the only constant being the large ocellus ("eyespot") in the middle of the back. The center of the ocellus is black or yellow, which is surrounded by concentric, alternating dark and light rings that may be either continuous or broken. The remainder of the upper surface is most commonly a shade of light brown with numerous fine dark dots; there may also be light dots, larger dark spots or blotches, and/or irregular brown marbling. Some individuals are plain light or dark brown with a black ocellus. The portion of the disc in front of the eyes is brown with up to five darker blotches. The dorsal pattern often extends to the ventral fin margins; the underside is otherwise white to cream-colored. This species grows up to long.