What are outstanding fea?tures of Contact lenses?

What are outstanding fea?tures of Contact lenses?

Contact lenses have two outstanding fea¬tures: they are placed on the eye balls (the way in which they are used) so that they become invisible (their physical property), and a cause-and-effect relationship can also be found in these two features. English speakers view them from the way that they are used, which is the cause, while the Chinese people are attracted to their invisibility, which is the effect.