An auto refractometer e sebelisoa ho lekola ho kopana ha leseli ka mor'a ho kena ka leihlong.E sebelisa boemo ba emmetropia joalo ka tekanyetso ea ho lekanya tekanyo ea phapang ea moeli le ho hasana pakeng tsa leihlo le hlahlobiloeng le emmetropia.Tse ling tsa rona auto refractometer e nang le keratometer, keratometer e sebelisa thepa e bonahatsang ea cornea ho lekanya radius ea curvature ea cornea.