Iav Teeb Tswm Teeb ntawm 6, Dia. 50 hli

Lub teeb muaj rau ntawm lub ntsiab muag tseem ceeb tshaj plaws., Nws suav nrog ib qho ntawm cov hauv qab no: plano-concave, convex-concave, ob chav concave, concave-convex, plano-convex, thiab ob npaug convex. ? Lub lens lens yog 50-hli kwv yees li.