CATS Tonometer Prism - Centration Reference Video.CATS Tonometer Prism precise centration feature appears di erent from GAT.Decentration is indicated by distorted mires. Adjust slit-lamp to center mires.Mires will appear normal and round when the CATS Tonometer Prism is centered ensuring accurate IOP measurement.For support call Reichert at 1-888-849-8955 or visit reichert.com/catsCast: Reichert Technologies