A prism is an optical component that serves one of two major functions: it disperses light, or it modifies the direction (and sometimes polarization) of light (1). In some cases, a prism has more than one function. Prisms are usually transparent to the region of the electromagnetic spectrum being observed.

How do prisms work?

A prism works because the different colors of light travel at different speeds inside the glass. ... The higher index of refraction means that violet light is the most bent, and red is then the least bent because of its lower index of refraction, and the other colors fall somewhere in between.

Where is prism used?

Mostly used in telescopes, periscopes and microscopes, scientists also use prisms in experiments that help them study the reaction of the human eye to light. Prisms constitute any three-dimensional shape with two faces of the same size and shape and parallelogram sides.