As the air grows crisper and the night grows longer, we're seeking the cozy comfort of the well-lit indoors. It's a good time to explore the decorative functions of light. I'm not talking about the pretty sparkle of a crystal chandelier or the artistic statement of a Tiffany lamp; I'm referring instead to the optical illusions and area-defining effects that light itself can achieve.

Light can change a rooms proportions, creating scale and volume to make it feel bigger, or visually shrinking it to a smaller, more intimate space. Strategically placed uplighting can wash the walls with light and reflect off of the ceiling to create a soft, diffused effect that mimics natural light, creating a roomy, airy feel. By illuminating opposite walls and leaving corresponding walls unlit, you can add the illusion of length to a room. Lighting something beyond the room, such as a patio or an adjoining room, can also trick the eye into perceiving more space than is actually contained within the room, adding to the feeling of openness.

Light can define areas and link spaces. In a loft apartment, for example, using track lighting to create pools of light and shadow of varying intensities can define zones and provide a feeling of distinct, separate areas for lounging, dining and sleeping. Conversely, using similar intensities of light in two separate but joined rooms, such as a living room and den, can draw the eye beyond the room's barrier and create the illusion of a single large space.

Light can create focus. Lighting focal points in a room, such as a painting, an architectural feature or a piece of designer furniture, is an easy way to create interest. It can be easy to get carried away, though, and create so many “focal” points that nothing stands out. A simple way to avoid this is, when planning the room's layout, use a yellow highlighter or sticky note to denote where your lighting focal points will be. If you end up with too much yellow, then you'll know that you need to be more discriminating about which aspects of the room to bring into focus.

When creating focal lighting, the point is to make the object being lit brighter than its surroundings in order to draw the eye; so the light source will need to be hidden so that it doesn't become the focal point, and it will need to be controlled separately from the room's primary light source so that it will remain bright when the other lights are dimmed.

This is just a small sampling of the effects that lighting can have on a space. In the coming weeks, we'll explore other ways to decorate, set mood and create drama with light.