The most common part of a magnifying lamp to wear out over time is the light bulb or the LED light source, depending on the type of lamp.
This is because the light source in a magnifying lamp is constantly in use, and like any light bulb, it has a finite lifespan. As the bulb or LED ages, it may become dimmer, flicker, or eventually burn out, making it less effective for magnification and illumination.
Therefore, replacing the light source is a routine maintenance task for magnifying lamps to ensure they continue to function properly.