Laser Pointer Awareness
Laser pointers are incredibly useful devices that have become ubiquitous in academic settings. However, this frequency of use--coupled with recent advances in the size and power of handheld laser devices--makes it imperative that laser pointer users be aware of the differences between "approved laser pointers" and more dangerous "handheld laser devices".
The Basics
Approved laser pointers must be Class IIIa lasers (or lower) with a maximum power output of 5 mW. The 5 mW power level represents the generally accepted threshold for eye protection by your natural blink reflex. Using "handheld laser devices" that exceed 5 mW as laser pointers puts both the presenter and the audience at risk for adverse eye damage should they receive an exposure to laser radiation. Recent advances in laser technology have led to the creation of "handheld laser pointers" that look indistinguishable from "approved laser pointers" and have power outputs of 1000 mW or greater (200x the approved limit).
How to Ensure Safety
Know your laser pointer! By law, all laser devices must be labeled to indicate their laser class and maximum power output. An example of a laser label can be found here. However, recent studies have demonstrated that devices mislabeled as Class IIIa are capable of power outputs that exceed 5 mW. Furthermore, prolonged exposure to a Class IIIa device is capable of resulting in retinal damage from long distances (at greater than 100 ft for 5 mW lasers). This means that even audience members at the back of the auditorium are at risk of eye damage if they receive a prolonged exposure. For these reasons, NEVER stare into a laser beam or direct a laser pointer toward the audience (regardless of laser class).
For more information, please see this Under the Microscope on laser pointers from December 2015.