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)
feeling or expressing regret or sorrow or a sense of loss over something done or undone; "felt regretful over his vanished youth"; "regretful over mistakes she had made"; "he felt bad about breaking the vase"