Question

what best describes the refraction of light rays?
light bouncing off of a mirror
light bending when it passes through a lens
light getting brighter when two waves combine
light passing through a clear glass window

Explanation:

Refraction is the bending of light as it passes from one medium to another (like from air to a lens). Light bouncing off a mirror is reflection. Light getting brighter when two waves combine is interference. Light passing through a clear glass window is just transmission. So the description of light bending when passing through a lens is refraction.

Answer:

light bending when it passes through a lens