Class 2 visible-light lasers are considered safe for unintentional eye exposure, because a person will normally turn away or blink to avoid the bright light. Do NOT deliberately stare into the beam — this can cause injury to the retina in the back of the eye.

Are Class 1 lasers safe?

A Class 1 laser is safe under all conditions of normal use. This means the maximum permissible exposure (MPE) cannot be exceeded when viewing a laser with the naked eye or with the aid of typical magnifying optics (e.g. telescope or microscope).

Are Class 4 lasers safe?

Class 4 visible-light lasers are significantly hazardous for eye exposure. They can cause burns to the retina. A person cannot turn away or blink fast enough to prevent retinal eye injury from a Class 4 laser. Prevent all eye exposure to beams from Class 4 lasers.