What term describes the dimming effect that results from a light source wearing down over time?

The term that describes the dimming effect resulting from a light source wearing down over time is lumen depreciation. This process refers specifically to the decrease in the amount of light output from a light source as it ages or experiences wear and tear. Various factors, such as thermal stress, contamination, and extended use, contribute to lumen depreciation, leading to a gradual reduction in brightness. Understanding lumen depreciation is essential for lighting design and maintenance, allowing for proper planning and replacement of fixtures to ensure consistent light levels in a given space.

Light decay refers to the reduction in light output over a shorter period or under certain environmental conditions, which does not account for the gradual aging process. Beam spread relates to the distribution of light from a source, indicating the angle at which light is projected, and is not directly associated with light output degradation. Voltage drop pertains to a reduction in voltage within an electrical circuit, which may affect performance but is not specifically tied to the aging process of the light source itself. Therefore, lumen depreciation accurately captures the concept of diminishing light output due to prolonged use and aging.