Ko te mohiti kanohi 1.74 te tikanga ko te arotahi he 1.74 te taupū whakaata, koinei te mea he nui rawa te tohu whakaata i runga i te maakete, me te mea he angiangi te matotoru o te arotahi.Ko etahi atu tawhā he rite, ka teitei ake te taupū whakaata, ka angiangi te arotahi, ka nui ake te utu.Mena he nui ake i te 800 nga nekehanga te tohu o te myopia, ka kiia ko te myopia ultra-tiketike, a he pai te tohu tohu o te 1.74.