Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What step can you take to extend the life of the bulb in a Goldmann perimeter?

1. Decrease the brightness setting

2. Store the bulb in a cool place

3. Rotate the bulb 180 degrees

4. Replace the bulb regularly

The correct answer is: Rotate the bulb 180 degrees

Rotating the bulb 180 degrees can help extend its life by ensuring even wear and tear on the filament inside. Many incandescent bulbs, including those used in Goldmann perimeters, can develop hotspots due to consistent usage without rotation. By rotating the bulb periodically, you allow different areas of the filament to be under stress, which can prevent early burnout and promote a more consistent level of luminance over time. This practice encourages a more uniform temperature distribution within the bulb, potentially doubling its lifespan and maintaining optimal performance for the device. While adjusting brightness settings can influence bulb longevity, it may not be practical for maintaining specific illumination levels required for accurate perimetry. Storing the bulb in a cool place is also beneficial, but primarily for transport and not directly during active use. Regularly replacing the bulb, though a necessary maintenance practice, does not extend its current life but rather adheres to a lifecycle protocol. Therefore, rotating the bulb stands out as a proactive step in prolonging its functionality.