Snell’s Law | AAOO

Optics teaching tool

Snell’s Law

Interactive ray and wavefront demonstration at a planar interface © Dr Grant Hannaford 2026

Explore refraction

Angles are measured from the surface normal. Wavefronts are perpendicular to the direction of propagation. Their spacing is proportional to wavelength in each medium.

Refracted angle
Critical angle
Wavelength ratio λ₂/λ₁

AAOO · Academy of Advanced Ophthalmic OpticsSnell’s law · Interactive learning