Prism Bar, solves a problem common to all ophthalmic practitioners. When examining a patient, it is necessary to know which diopter prism is currently held in front of the eye. Before Prism Bar, this required turning and looking at the side engraving on the bar for the diopter number. Over time, these wasted seconds can add up to significant monetary loss for a practice. Prism Bar solves this problem. With the diopter numbers engraved in the plane of the prism, rather than on the side, the practitioner does not have to change positions to view the number.