Eye-cup

Chalkidian black-figure eye-cup, circa 530 BC, Munich: Staatliche Antikensammlungen.
Dionysos on a boat, sailing amongst dolphins. Attic black-figure kylix by Exekias, circa 530 BC. Found at Vulci. Dionysus cup: Staatliche Antikensammlungen, Munich.
Outside of the Dionysus cup

Eye-cup is the term describing a specific cup type in ancient Greek pottery, distinguished by pairs of eyes painted on the external surface.