Why are barriers or shields used with luminaires?

Barriers or shields are used with luminaires primarily to protect against accidental contact with live electrical components and to reduce glare, which can be uncomfortable or hazardous for individuals in the area. By obstructing direct light paths, these components help manage light distribution, making the environment more visually comfortable while ensuring that the luminaire operates safely. Additionally, they help to prevent unauthorized access or accidental exposure to potentially dangerous parts, thereby enhancing the overall safety of the lighting fixture.

The other options do not align with the primary functions of barriers or shields. Enhancing light brightness is not a goal of these protective components; in fact, some barriers can reduce the intensity of light output to mitigate glare. Decorating the luminaire is a secondary consideration that does not address the primary functions of safety and comfort. Increasing energy consumption is contrary to the goals of modern lighting design, which aims to maximize efficiency and minimize unnecessary energy use.