- A piece of glass, or other transparent substance, ground with
two opposite regular surfaces, either both curved, or one curved and
the other plane, and commonly used, either singly or combined, in
optical instruments, for changing the direction of rays of light, and
thus magnifying objects, or otherwise modifying vision. In practice,
the curved surfaces are usually spherical, though rarely cylindrical,
or of some other figure.
Meaning of 'lens' (Princeton's WordNet)
1 . lens
[ n]
Meaning (1): - (metaphor) a channel through which something can be seen or understood
Example in sentence:
the writer is the lens through which history can be seen