Two Laws of Refraction:

First Law:
When a ray of light passes from one medium to another, it bends towards or away from the normal depending on the difference in the optical densities of the two media. This bending of light is known as refraction. The first law of refraction states that the incident ray, the refracted ray, and the normal to the interface of two media at the point of incidence, all lie in the same plane.

Second Law:
The second law of refraction states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant for a given pair of media. This constant is known as the refractive index of the second medium with respect to the first medium. Mathematically, this can be expressed as:
n₁sinθ₁ = n₂sinθ₂
where n₁ and n₂ are the refractive indices of the first and second media, and θ₁ and θ₂ are the angles of incidence and refraction respectively. This law helps us understand how light bends as it passes from one medium to another.
Understanding and applying these two laws of refraction is essential in various optical applications such as lenses, prisms, and fiber optics. These laws help us predict and analyze how light behaves as it travels through different mediums, allowing us to design and optimize devices for various purposes.