Lub OptoTech SD kev txhim kho lub lens tsim nthuav dav qhov tsis xav tau astigmatism hla thaj chaw loj ntawm lub lens saum npoo, yog li txo qhov dav dav ntawm qhov muag plooj ntawm tus nqi ntawm kev nqaim thaj tsam ntawm lub zeem muag pom tseeb.Qhov yuam kev astigmatic tseem tuaj yeem cuam tshuam rau thaj chaw nyob deb.Yog li ntawd, softer progressive lo ntsiab muag feem ntau qhia cov yam ntxwv hauv qab no: cov cheeb tsam me me, dav nyob ze ntawm thaj chaw, thiab qis dua, maj mam nce qib ntawm astigmatism (dav dav contours).Qhov max.tus nqi ntawm pliaj astigmatism yog txo mus rau ib qho zoo kawg theem ntawm approx.75% ntawm lub zog ntxiv.Qhov kev tsim qauv no yog ib feem siv tau rau cov chaw ua haujlwm niaj hnub.