Garage door openers generate a lot of vibration, and that can cause the light bulbs in them to fail much sooner than you'd like. If you have that problem, replace the bulb with a "rough service" model. Though they cost a bit more than standard incandescents, rough service bulbs have a beefed up filament that will hold up better to all the shaking it receives. And if the bulb lasts longer, you'll make up the price difference over time. I've seen rough service bulbs from both GE and Sylvania.
For other problems with your garage door opener, take a look at Troubleshooting the Most Common Garage Door Opener Problems.
Photo © Jeff Beneke