Prism principle

Sunlight is polychromatic light with different frequencies of red, orange, yellow, green, indigo and purple. These have different refractive indexes for the same medium, so a beam of light will be refracted at different deflection angles after entering the prism (the law of refraction of light.

The sine of the incident angle is proportional to the sine of the refraction angle, and the proportional coefficient is the refractive index), so the light beam propagating in one direction will be decomposed into light bands arranged in the order of deflection angle. (Deflection angle = refraction angle-incident angle. In the above case, the incident angles of light with different frequencies are the same. )

Extended data:

Application of prism in life;

Surgical correction and prism correction are the main clinical treatments for nonadjustment strabismus. Parents have many questions about how to choose these two treatments. correct

Children with horizontal strabismus ≥ 15△ and vertical strabismus ≥ 10△ can be surgically corrected in principle. Especially for children whose binocular stereopsis is affected, early surgical correction is helpful to re-establish binocular stereopsis.

However, the prism itself has some limitations, such as the thickness of the lens, one eye can only match the degree below 7△, and the object is deformed. These problems also limit the clinical application of prism.

Baidu Encyclopedia-Prism (an optical instrument with a triangular cross section)