双凸面 Traditional 雙凸面 shuāng tū miàn 🔊 convex on both sides (of lens) + Review this word Meanings shuāng tū miàn 雙凸面 convex on both sides (of lens)biconvex Its characters 双shuāngtwoHSK 3凸tūto stick outHSK 7–9面miànfaceHSK 2