Question

why does direction changes when medium is changes light​

Answer 1

Answer:

The change of direction of light as it passes from one medium to another is associated with a change in velocity and wavelength. The energy of the light is unchanged as it passes from one media to another. When visible light in air enters a medium such as glass, the velocity of light decreases

Explanation:

Answer 2

Answer:

Refraction. 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. My personal opinion is that light does not move slower through matter, it travels through more space.