The Impressionists, Monet and Degas and the rest of them, chased the light. They tried to capture it, harness it, view the world through its lens. They used opaque pigments to give the impression of it — something dark and thick to make you think of illumination. Monet, for example, spent an enormous amount of time painting the cathedral of Rouen over and over, in various lights, in various seasons. The building remained the same, but it looked different depending on the time of day or what the weather was doing. Monet was entranced by this.
If a building is well thought-out, it treats light the same way the Impressionists did. Light is invited in, gently, appropriate to season and the use of the room. Light can make a home feel airy, expansive, elegant, restful or invigorating. There are many things to consider in a home design, and natural light is crucial.