Diagnosis
Excessive vibration from the opener unit is shaking the filament. The 54930 uses a standard medium base incandescent bulb.
How to Fix It
Replace the standard bulb with a rough service incandescent bulb or an LED bulb rated for garage door openers. These have thicker filaments or no filament at all. Ensure the bulb is snug but not overtightened.
If That Didn't Work
Check the bulb socket for arcing or corrosion. A poor connection causes heat and voltage spikes. Unplug the opener. Inspect the socket. Replace the socket or the entire light fixture if contacts are burnt.
Heads Up
Do not exceed the recommended wattage (the unit is rated for a 100W max). A higher wattage bulb creates excess heat that can damage the lens and wiring.