Specifications: Working distance: 2-6.5 meters with an incremental value of 0.1 meters; Color blind test available; 21.5” high-resolution screen display; User-friendly setting interface to customize the language, working distance, R/G test; brightness adjustment; mirror function, and standby time. 2 sets of programmable optotype charts are available Randomized charts are available to avoid memorization for accurate testing ; Update via USB is available
