The Humphrey FDT Model 710 frequency doubling technology perimeter is a "Humphrey" visual field in a small, compact and easy-to-use desktop instrument. With minimal set-up time and test times as low as 45 seconds, the Humphrey FDT is fast enough to screen all of your patients. For positive screening results, threshold tests provide additional diagnostic information. The 19-pound tabletop Humphrey FDT is portable, easy to operate, and can be used in normal lighting conditions and without trial lens correction. The Humphrey FDT is an excellent choice for glaucoma screening and is small enough to be used for remote screening events.