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)
an unexpected and inexplicable change in something (in a situation or a person's behavior, etc.); "the vagaries of the weather"; "his wealth fluctuates with the vagaries of the stock market"; "he has dealt with human vagaries for many years"