Why can uniform overhead lighting make an interior feel monotonous?

Uniform overhead lighting can make an interior feel monotonous because it lacks the necessary variety of highlights, shadows, and accent lights that provide character and interest to a space.1

While an even, overall lighting system—such as a luminous ceiling—can be highly efficient for illumination, it fails to create the dynamic visual experience required to define a space's atmosphere. Effective interior design relies on the interplay of light and shadow to mold and shape a room, much like the way daylight creates changing patterns and intensities through high windows or stained glass. Without this variation, a space loses its ability to suggest mood or provide a sense of depth, resulting in an environment that feels dull rather than engaging.12