# How does light change directions? [duplicate]

To the best of my knowledge, light will always travel at the speed of light. How then does it get reflected and change directions? Wouldn't it have to decelerate, come to a stop, and then accelerate in the opposite direction?

Or would the direction of motion be discontinuous when graphed as a function of time?

At a classical level light can interact with electric charge distributions as described by Maxwell's equations. This can be used to explain lens optics which relies on light travelling slower than $c$ in a dielectric medium. To reconcile this apparent contradiction that light should travel slower than $c$, a microscopic picture is needed. I refer you to this stackexchange post for more details on why the speed of light is not $c$ in a dielectric medium.