For nighttime readers, directional light is useful: “If you’re gonna be reading in bed, I think it’s really important to have lighting that’s adjustable,” says interior designer Liz Lipkin.

Light that comes from all directions. Contrast with "directional lighting," which is made up of a light source with parallel light rays that do not diminish with distance. Also, contrast with ...

thus demonstrating that the emission of light is not equally distributed in all directions of space, but some are preferred ...