Kuonana lens, kana kungotaura kuonana, chinhu mutete izvo yakaiswa zvakananga pamusoro ziso. Contact lenses vari okuona prosthetic mano anoshandiswa nevanhu vanopfuura mamiriyoni 150 munyika yose, uye vanogona kupfekwa kururamisa maonero, nokuti zvizorwa, kana kurapa zvikonzero. Muna 2004, zvaifungidzirwa kuti 125 miriyoni vanhu munyika yose vanoshandisa kuonana lenses, kusanganisira 28 kusvika mamiriyoni 38 muUnited States. Muna 2010, munyika yose musika kuti kuonana lenses yaifungidzirwa pa $ 6.1 bhiriyoni, apo US nyoro lenses musika yaifungidzirwa pa $ 2.1 bhiriyoni. Multiplests vanofungidzira kuti pose musika kuti kuonana lenses aizosvika $ 11.7 bhiriyoni kubudikidza 2015.
Mamiriyoni 125