What class of lasers can cause immediate eye injury?

Class 3B lasers are known to be capable of causing immediate eye injury upon exposure. This is primarily because they emit high levels of visible or invisible light that can damage the retina or other parts of the eye very quickly. The risk of injury is significant enough that even brief exposure can lead to permanent damage, particularly for individuals who do not use appropriate protective eyewear or safety precautions.

In contrast, Class 1 lasers, which are considered safe under all conditions of normal use, have very low power outputs and are not capable of causing eye injury. Similarly, Class 2 lasers, while potentially hazardous because they can emit visible light, are typically safe for short, accidental exposure as the natural aversion response (blinking) tends to protect the eyes by limiting exposure time. Class 3A lasers may pose some risk, but they typically require more prolonged exposure to cause eye injury compared to Class 3B lasers. Thus, Class 3B lasers represent a significant hazard, especially in environments where proper safety measures are not adhered to.