Class 2 lasers are deemed safe under what condition?

Class 2 lasers are deemed safe primarily under conditions of brief exposure. This classification falls under the category of low-power lasers that emit visible light, typically in the range of 400 to 700 nanometers. The rationale behind the safety aspect of Class 2 lasers is rooted in the human eye's natural aversion response to bright lights. When a person is exposed to a Class 2 laser and it is shone in their line of sight, they are likely to blink or look away within a fraction of a second, thus minimizing the potential for harm.

It is important to understand that while Class 2 lasers can be safe for brief exposure, constant exposure could lead to eye damage due to prolonged illumination. Similarly, long-term viewing would exceed the safe exposure limit due to the possibility of retinal burns or other injuries. The lighting conditions, such as only being deemed safe in dim lighting, do not influence the classification of the laser itself or its inherent risks to the eyes. Thus, brief exposure is the key condition that governs the safety status of Class 2 lasers.