Question

Light changes direction slightly when passing from one substance to another?

Answer 1

When a ray passes from air into glass the direction in which the light ray is traveling changes. ... This bending of a ray of light when  passes from one substance to another substance is called refraction. Hope this helps!!!

Answer 2

Answer:

This phenomenon is known as Refraction.

Explanation:

Light waves change speed when they pass across the boundary between two substances with a different density, such as air and glass. This causes them to change direction, an effect called refraction.

At the boundary between two transparent substances:

the light slows down going into a denser substance, and the ray bends towards the normal

the light speeds up going into a less dense substance, and the ray bends away from the normal