What term measures the intensity of lighting in a specific direction?

The term that measures the intensity of lighting in a specific direction is luminance. Luminance quantifies the amount of light that is emitted, passed through, or reflected from a surface and is perceived by the human eye. It is expressed in candelas per square meter (cd/m²) and is crucial in evaluating how bright a surface will appear based on the direction of the light. Understanding luminance is essential for effective lighting design, as it directly impacts visibility and visual comfort in a space.

While glare refers to excessive brightness that causes discomfort or reduced visibility, ambience relates to the overall atmosphere of a space, and lumens measure the total quantity of visible light emitted by a source without directionality. Therefore, the focus of luminance on specific directional intensity distinguishes it as the appropriate term in this context.