Wave refraction: process by which the direction of approach of a wave changes as it moves into shallow water.

UNESCO: L O S S A R Y

"Light in transmission, reflection and refraction as it is perceived, " as he states on his website, inspires all of his design work.

WSJ: Robert Zimmer | Where Theory and Practice Make Perfect | Cultural Conversation by Joel Henning

The flash itself is actually a second image of the sun, caused by refraction of its light through the layer of air closest to the sea.

ECONOMIST: In a flash

This refraction eliminates both the red end of the spectrum (red light is not bent enough by the air layer to form part of the second image) and the blue frequencies (which are scattered away: this selective scattering is why the sky is blue).

ECONOMIST: In a flash