How does light accelerate back to its original speed after refraction from another medium e.g. glass or water

Question

The speed of light slows as it traverses through a different medium, but after slowing it finds a way to accelerate back to original speed as it exits that medium. How does it do that?

In: 93

Answer 1

Photons, when traveling through a medium, create secondary waves through the vibrations of atoms of the medium. When taken together the resulting wave is slower than the speed of light.

Light does not accelerate going into or out of a medium.