Creating conical shaped structures (Moth's Eye structures) that are smaller than the transmitted wavelength minimizes reflection by creating a gradual change in the effective refractive index.
The antireflection structures have the same effect as an antireflection coating.
Generally, reflection percentage increases the bigger the difference in refractive index between the air and the optic.
The microscopic conical geometry results in a smaller refractive index change from the vertex to the base of the cones resulting in greatly reduced reflection.
Applications requiring high reliability such as automotive or in the broiling sun
High incidence angle dependent optical systems