A lens works by refraction of light, i.e. bending of light when it crosses a surface.
(it; crosses; a surface) (A lens; works; ) Context(A lens works,List([0, 12))):(A lens; works i.e. bending; of light; T:when it crosses a surface)
A lens works,List([0, 12))
it A lens A lens
crosses works works i.e. bending
a surface
of light T:when it crosses a surface