Clouding of the lens, much like smearing grease over the lens of a camera, can develop at any age but most often appears in people older than 42.

• 晶状体变混浊，就如同相机的镜头上涂上了油脂，这种现象可能会出现在不同年龄层的人群中，但是以42岁以上的人群为主。