A Auto Decuctometer imagwiritsidwa ntchito poyang'ana mogwirizana ndi kuwala mutalowa m'maso. Imagwiritsa ntchito mkhalidwe wa Emmetropia monga muyezo woyeza kuchuluka kwa kusiyana ndi kubalalika pakati pa diso loyesedwa ndi Emmetropia. Ena athu Auto Decoctometer ndi Keratometer, keratometer imagwiritsa ntchito mawonekedwe a majerenema kuti ayesetse radius wa cornea.