the eye unaided by any optical instrument that alters the power of vision or alters the apparent size or distance of objects; "it is not safe to look directly at the sun with the naked eye"
increased pressure in the eyeball due to obstruction of the outflow of aqueous humor; damages the optic disc and impairs vision (sometimes progressing to blindness)
providing protective supervision; watching over or safeguarding; "daycare that is educational and not just custodial"; "a guardian angel"; "tutelary gods"