Proven Accuracy Convenient and versatile, the Perkins Tonometer offers proven accuracy and brilliant visibility. Counterbalanced movement allows accurate readings to be taken in any orientation. Perfect for bed-ridden patients. Features Convenient and versatile. Operation is easy when user is familiar with Goldmann tonometry Proven accuracy and brilliant visibility Optional Perkins Examination Telescope (P.E.T.) allows magnified viewing of the fluorescein “semi-circles” at arms length Standard with “AA” batteries