Polarized sunglasses are a type of sunglasses.Polarized light can be divided into three types: linear, elliptical, and circular.

Generally the so-called polarized light refers to linear polarized light, also known as plane polarized light.The vibration of the light wave is fixed in a particular direction, and its propagation path in space is a sinusoidal curve, and its projection on the plane in the vertical propagation direction is a straight line.
The plane composed of the direction of linear polarization vibration and the direction of propagation is called the vibration plane, and the plane perpendicular to the direction of vibration and containing the direction of propagation is called the polarization plane.Linear polarized light can be obtained by passing natural light through a polarizing mirror, which is often used in crystal optics research.