Purpose and Scope
This field manual provides basic preventive,
protective, and diagnostic information on laser injuries. The
treatment procedures described herein are for use by combat medics,
battalion aid station personnel, and other medical treatment
facilities without an Ophthalmologist.
Also, an evaluation matrix is provided for
use by combat lifesavers and combat medics. Once an individual has
been diagnosed as having a severe laser injury, causing loss of
vision, he will be prepared for evacuation to a medical treatment
facility where he can receive specialized care for his injury.
a. The word “laser” is an acronym for
“light amplification by stimulated emission of radiation.” In common
usage, a laser is a device that produces an intense, narrow beam of
light. Normally each laser can only produce a single frequency or
color of radiation. However, there are many different types of lasers.
Some produce light which is in the visible portion of the radiation
spectrum and, therefore, can be seen. Others produce radiation which
is outside of the visible spectrum (either infrared or ultraviolet)
and is, therefore, invisible. Appendix A depicts the wavelength of
common lasers. Some laser devices produce radiation with sufficient
energy to severely injure or burn the eyes or skin of personnel who
are down range. The use of laser devices, such as rangefinders and
target designators may result in accidental injury to the eye.
Appendix A also depicts some of the lasers commonly found in the
United States Army. It is possible that similar devices may be used by
opposing forces as antipersonnel weapons.
b. The beam of light emitted from a
laser device is normally very narrow, usually less than an inch in
diameter. However, over long distances, the beam progressively becomes
wider. For a military laser, the beam is typically 1 meter in diameter
at a distance of 1 kilometer and 2 meters in diameter at a distance of
2 kilometers. Thus, a laser can irradiate the whole body at these
distances. If the energy of the laser is high enough, such exposures
could burn clothing, skin, or any part of the body exposed to the
beam. Most lasers, however, are not powerful enough to generate burns.
Because the eye focuses and concentrates whatever light that enters
the eye, it is extremely sensitive to injury from almost any type of
laser device. The concentration of energy which is focused onto the
back of the eye can be 100,000 times greater than the energy which
enters at the front of the eye. Thus depending upon the type of laser,
the energy output of the laser, and the distance from the laser, a
spectrum of injuries can be expected. These may range from very tiny
lesions in the back of the eye to severe burns affecting vast portions
of the body. See Appendix A for principal wavelengths of common
c. Injuries to the eye result when the
energy from the laser is absorbed by various anatomical structures.
The frequency of the laser radiation determines which structure
absorbs the energy (Figure 1).
(1) Ultraviolet. Lasers operating in
the ultraviolet spectrum (below 400 nm UV-A,B,C) are absorbed in the
anterior segments of the eye, primarily by the cornea, as well as by
(2) Visible. Laser radiations in the
visible spectrum (400-700 nm) are absorbed primarily within the retina
by the pigment epitheliums and the choroid.
(3) Infrared. Absorption of lasers in
the infrared spectrum occurs in two areas of the eye. Lasers at the
near-infrared spectrum (700-1400 nm IR-A) damage the retina and the
choroid, whereas light in the far-infrared spectrum (above 1400 nm
IR-B,C) damages the cornea.