An interface Desigh Realizing Smooth Communication and Superb Operability Overview Speedy, Smooth & Silent High quality and ultra-reliable optical parts allow faster, smoother and quieter measurement through the high-precision mechanism design, featuring a sequential-control lens rotating unit. This refractor is based on a human-interface design, prioritizing user-friendliness e.g. by focusing on operation "noise". Smart & Slim The head unit incorporates all required optical functions as well as enabling a smart, slim and compact design. Smooth and comfortable measurement is possible without exposing patients to any feeling of pressure.