|The speed of light isn't always the same. It actually slows down when it moves through some transparent
materials, like glass or water. When light slows down, it changes direction. This "refraction" of light is the reason a straw in water looks bent or broken
and why objects viewed through a glass bottle appear distorted.
In the same way light reflects differently off different surfaces, it also refracts differently depending on the shape of the material. This can make refraction very useful. For example, the curve of eyeglasses directs light rays into the eyes more effectively. Magnifying lenses also use refraction: the convex lens bends the light rays so the image appears larger.