Lasers and the Eyes

LASER: Light Amplification by Stimulated Emission of Radiation

  • Laser wavelengths are measured in nanometers (nm = one billionth of a meter or 10-9m).
  • Laser energy is coherent, monochromatic and collimated, posing both skin and eye hazards, depending upon wavelength and power.


  • Retinal Hazard: From 400nm to 1400nm, the eye is 100,000 times more vulnerable to injury than the skin. Due to the focusing properties of the eye, irradiance in this region of 1mW/cm2 entering the eye irradiates the retina at 100W/cm2.
  • Corneal/Lens Hazard: UV (190-400nm) and Mid/Far IR energy (1400-11,000nm)pose corneal/lens and skin hazards.

Images courtesy of LIA

Laser safety goggles, windows and barriers provide some levels of protection against injury from accidental and/or incidental direct or diffuse exposure to laser energy.