角膜上皮正常代谢时所需的能量,主要是靠醣类的有氧分解,赖此以维持角膜的透明。如氧气不足时,上皮需通过无氧酵解来取得能量。当不能维持其正常代谢时,角膜即变厚并丧失其透明性。有机玻璃制成的角膜接触镜戴在角膜上,使角膜上皮前的液膜层与空气隔绝, Corneal epithelial energy required for normal metabolism, mainly by carbohydrate aerobic decomposition, in order to maintain the transparency of the cornea. In case of insufficient oxygen, the epithelium needs energy through anaerobic glycolysis. When it can not maintain its normal metabolism, the cornea becomes thick and loses its transparency. Contact lenses made of plexiglass wear on the cornea, the corneal epithelium before the liquid film layer and the air isolated,