3-3/8x7” card used by Optometrists in the diagnosis of eye problems or to be used in a self-administered program to improve one’s own visual acuity. The two images of Babe about to swing the bat and of a man jumping from a rock each have horizontal and vertical white line markers which when seen overlapping as a plus sign would determine a lens specification. Text on reverse side “The Keystone Eye Comfort And Depth Perception Series ©Keystone View Co. Meadeville, Pa. Card is slightly curled with age, o/w Exc. Unique Ruth item.