Key enzyme in the cholesterol biosynthesis pathway. Catalyzes the cyclization of (S)-2,3 oxidosqualene to lanosterol, a reaction that forms the sterol nucleus (PubMed:14766201, PubMed:26200341, PubMed:7639730). Through the production of lanosterol may regulate lens protein aggregation and increase transparency (PubMed:26200341). {ECO:0000269|PubMed:14766201, ECO:0000269|PubMed:26200341, ECO:0000269|PubMed:7639730}. This is the function of ENSG00000160285 (LSS, lanosterol synthase).