Penetration is limited - target organs are the skin and cornea , although the immune system may also be affected. UVB or Actinic UV, the mid-frequencies, are the most damaging. Intense acute exposures, and possibly less intense cumulative exposures can cause cataracts. The TLV is designed to protect against thermal retinal injury. Mild flash blindness is common.
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.