Pulsed light can cause epileptic seizure in susceptible persons. Other indirect effects include changes to circadian rhythms. The sun, lasers, flash lamps, and welding and carbon arcs. Far, Middle, and Near IR can penetrate to the eyes' cornea, lens and retina, respectively. The TLV is designed to protect against cataracts , such as glassblower's or furnaceman's cataract.
Hazard varies with intensity and duration of exposure and type of radiation.
Primarily an eye and skin hazard. Normal protective mechanisms, such as pain, may be too slow to prevent damage. Visible, near UV and near IR lasers can damage the retina. High intensity pulsed emissions can cause mechanical destruction to retina and choroidal tissues. Class 2a Class 2 lasers safe for 1000 sec of exposure to eyes.