Eyes were the primary visual organ of many sentient and animal species. Most species possessed a single pair of eyes located on their head, although some species, such as Abyssin, had only one eye, and others, like the Harch and the Dyplotid, possessed several pairs. Yet other species, like the Melitto from Li-Toran, or Miraluka like Prosset Dibs, had no eyes at all, relying on other organs to navigate. The droid equivalent to an eye was a photoreceptor.
When tutoring Luke Skywalker in the use of the Force, Obi-Wan Kenobi warned him that his eyes could deceive him and suggested not to trust them. To prove his point, he blindfolded Skywalker, after which Skywalker was successful in deflecting shots from a training remote with his lightsaber by drawing upon the power of the Force.
After the redeemed Anakin Skywalker was mortally wounded killing the Emperor to save his son, his last request was for Luke to remove his helmet so that he could look on his son with his own eyes, instead of through the filters of his mask.
Kanan Jarrus' eyes were destroyed by Maul with his lightsaber, rendering him blind. Cybernetic replacements were available, however, as shown by Clone Commander Wolffe, whose right eye was destroyed by Asajj Ventress.[source?]