He only created bifocals because he was too lazy to switch between different pairs of glasses.

就因为他懒得换眼镜戴，于便光眼镜。

There are eyes with lenses made of rock, eyes with built-in bifocal lenses, eyes that can look up and down at the same time.

有眼睛晶体石头，有眼睛里晶体，还有眼睛可以同时上下看。

If somebody already requires distance correction, often they'll be be fitted with bifocals or contacts with two different types of lenses: one for far and one for near.

这时若需要矫正，他们通常需要配戴光眼镜，带有两种镜片：一种看远距离、一种看近距离。