Now we're going to talk about refraction of light.

今天我们要讲的是光线的折射。

In conversation La Farge's mind was opaline with infinite shades and refractions of light, and with color toned down to the finest gradations.

在谈话中，拉法奇的头脑是乳白色的， 有着无限的阴影和光线的折射， 颜色被调到最精细的层次。