These eyes were placed over the face of the deceased, as part of the typical funerary ceremony in Ancient Egypt.
The production of death or funerary masks was customary as early on as the Old Kingdom. During the Middle Kingdom, great consideration was given to the appearance of mummies, and the use of funerary masks increased. In the New Kingdom, anthropoid coffins became the norm, and the masks of the mummies often had their eyebrows and eyes inlaid, rather than painted.
These large eyes probably also served to represent the eyes of the falcon god, Horus, serving as protective symbols against perils during the mummy’s journey to the Underworld.