Lumens are not directly equivalent to the intensity of lighting, but rather a measure of the amount of light emitted by a light source. In simple terms, lumens describe how much light a light source "emitted", but do not necessarily reflect the "brightness" of the light.

Generally speaking, when the LED bulb reaches the specified life span (such as 25,000 hours or 50,000 hours), its brightness will drop to about 70% of the initial brightness, and the LED bulb needs to be replaced at this time.