Umgangatho we-substrate umisela ukuqina kwe-lens kunye nokuthembeka kwengubo.I-substrate elungileyo ecacileyo kwaye eqaqambileyo, ixesha elide lokusebenzisa kwaye akukho lula ukutyheli;Kwaye ezinye iilensi azisebenzisi ixesha elide kumthubi, okanye ukugquma.Ilensi elungileyo ngaphandle kwemikrwelo, imikrwelo, umphezulu woboya, imingxuma, ilensi egudileyo ukuhlangabezana nokuqwalaselwa kokukhanya, ukugqiba kuphezulu kakhulu.Akukho ndawo, ilitye, umgca, i-bubble, i-crack ngaphakathi kwi-lens, kwaye ukukhanya kukhanyayo.
I-index ye-refractive ephezulu, i-lens encinci, kunye nexabiso eliphezulu.