It is then refracted away from the normal at the boundary between glass and air as it leaves the prism.

The incident ray is refracted towards the normal as it enters the glass prism from air. It is then refracted away from the normal at the boundary between glass and air as it leaves the prism.

The important property of prisms in this article is their ability to redirect light through refraction and reflection. A collection of deck lights used to direct sunlight below deck in ships.