Under what conditions will light bend?

Light refracts or bends when it leaves one medium and enters another one (ex. when it goes from air to water; or when it goes from glass to air). This is because the speed of light is different in different materials (light travels in a vacuum at a speed of 3 x 10^8 m/s and is slower in all other mediums). When light slows down (ex. moves from air into water), the light bends towards the normal; when light speeds up (ex. moves from water into air), the light bends away from the normal.

Light has a unique property that when it travels from one transparent medium to another transparent medium of different densities it bends and this property is known as refraction

for eg from water to air wherevelocity of light in water is2.25x 10 raised to power 8 m/s and velocity of light in air is3x10 raised power 8 m/s