The laws of refraction of light are as follows:

•  The incident ray, refracted ray and normal lie in the same plane.
• Light bends towards the normal when passing from rarer to denser medium, and bends away from the normal when passing from denser to rarer medium.
• The ratio of sine angle of incidence to the sine angle of refraction is always constant. This law is known Snell's law.

\(\rm µ\)= $\frac{sin i}{sin r}$

• When light ray incidents normally, it passes without bending.