A I-Auto RefActometer isetshenziselwa ukubheka ukuguqulwa kokukhanya ngemuva kokufaka i-eyeball. Isebenzisa isimo se-Emmetropia njengeZinga ukukala izinga umehluko ngokuhlukahluka nokuhlakazeka phakathi kwamehlo ahloliwe kanye ne-eMMETROPIA. Ezinye zethu I-Auto RefAckometer ngeKeratometer, iKeratometer isebenzisa izakhiwo ezibonisayo ze-cornea ukukala irediyo ye-curvea.