A I-lensmeter noma i-lensometer, eyaziwa nangokuthi i-focimeter noma i-vertometer, iyithuluzi le-ophthalmic. Isetshenziswa kakhulu odokotela bamehlo nodokotela bamehlo ukuze baqinisekise incwadi kadokotela elungile ezingilazini zamehlo, ukukhomba ngendlela efanele nokumaka amalensi angasikiwe, kanye nokuqinisekisa ukukhwezwa okulungile kwamalensi kumafreyimu ezibuko.