Working Distance 12.5mm Corneal Coverage 0.9 mm to 10 mm Dioptric Range 9-99 Diopters Resolution 0.01 Diopters / 1um Reproducibility +/- 0.10 Diopters* *measured on a verified test object. Specifications subject to change without notice EyeSys Topography Systems set the standard for the next generation of corneal topographers with truly affordable pricing while retaining the high quality and excellence that are the hallmark of EyeSys Products. Utilizing a single software platform to communicate with either device makes upgrading or working with a satellite office a snap. Fast and Easy-to-Use Plug and play design Automatic exam acquisition Intuitive user interface Accurate and Reproducible 25 Placido rings - 9000 data points State-of-the-art image processing Error forgiving video stream acqusition Calibration verification Full-Featured Software Axial, tangential, refractive and elevation maps Simulated K-readings Holladay Diagnostic Summary with surface distortion map Keratoconus detection indices with asphericity coefficient High order aberrations map Contact Lens Map and other numeric maps White to white measurement Database can store data from either device Compatible with standard USB 2.0 notebook or desktop computers, EyeSys Topography Systems leverage many features of Microsoft Windows. The software is compatible with Microsoft's XP, Vista and Windows 7 & 8 operating systems. With the exception of the joystick base, all EyeSys Systems are soild state with no moving parts making them dependable and easy to service.