Refraction of light is the phenomenon of bending of light as it travels from one medium to the other. When a ray of light travels from one transparent medium to the other it bends at the surface, this is due to the different optical density of different medium.
The figure below illustrates the refraction of light.
![](https://www.sarthaks.com/?qa=blob&qa_blobid=10575562093425744552)
Snell’s Law states that ratio of sine of angle of incidence and angle of refraction of two medium is always constant.
Mathematically it is given as
\(\frac{sin\,i}{sin\,r}=constant=\,^aμ_b\)
aμb = is the refractive index of medium a with respect to medium b