The treatment is to remove the clouded lens and replace it with a permanent plastic lens.
其治疗方法是摘除混浊的晶状体，换上永久性的塑料晶状体。
2
Large, dense cataracts present from birth in the middle of the lens that affect only one eye are more likely to cause permanent vision loss.
若白内障较大而致密，且位于一侧眼球的晶体正中，这种情况更容易造成永久性的视力丧失。
3
When the sun's rays passed through a lens in one of the walls, Leonardo's 3D model would have been projected on to the material, creating a permanent image.