1|Page
LASER SAFETY OFFICER – BEO 2026|
COMPREHENSIVE QUESTIONS AND
ANSWERS
What is the thermal damage process associated with? - correct-answer - Class 4
laser. Exposure time >10 microseconds in wavelengths from near ultraviolent to
far infrared.
Thermal is the most common cause of laser-induced tissue damage.
It ranges from mild sunburn to blistering and charring.
What effect is unique to pulse lasers in regards to tissue damage? - correct-
answer - The photochemical effect. It causes tearing of the tissue.
Why are the eyes susceptible to laser damage? - correct-answer - The eye focuses
the laser onto the retina, amplifying the laser source.
,2|Page
What does the damage to the eye depend on? - correct-answer - It depends on
the power and wavelength of the beam.
Cornea - Far UV, 100-300nm, damages the cornea through photochemical effects.
Causes kerato-conjuctivitis.
Cornea - Far-IR - >1400nm Causes damage to the cornea through thermal damage
Cornea/lens - near-UV 300-400nm - absorbed by the lens, can cause cataracts.
Retina damage - Visible range/near IR, 400-1400 nm - Magnified by the eye so
lower levels can cause more damage. Causes thermal burns and bleeding
Extended source viewing of diffuse beams can lead to large scale/lower level
damage.
This is the level of laser radiation to which a person can be exposed without
hazardous effects or adverse changes in the eye/skin. - correct-answer - MPE
Maximum Permissible Exposure
Depends on Wavelength, Exposure Duration, Output, and exposure conditions.
J/cm2 - Pulse
, 3|Page
W/cm2 - Continuous
What is the difference between an extended source and a point source? - correct-
answer - It is based on the angular subtense. The further away a source is, the
more it is a point source. It focuses on a small spot of the retina. An extended
source is very close and the energy is spread across the retina.
How do we calculate the MPE? - correct-answer - There are values within the
ANSI standard, but in addition to that, we also need the anticipated exposure
value. They are different depending on the laser.
UV is all day
Visible is 0.25 sec(aversion response)
IR is 10 sec
Single Pulse is the pulse width
LASER SAFETY OFFICER – BEO 2026|
COMPREHENSIVE QUESTIONS AND
ANSWERS
What is the thermal damage process associated with? - correct-answer - Class 4
laser. Exposure time >10 microseconds in wavelengths from near ultraviolent to
far infrared.
Thermal is the most common cause of laser-induced tissue damage.
It ranges from mild sunburn to blistering and charring.
What effect is unique to pulse lasers in regards to tissue damage? - correct-
answer - The photochemical effect. It causes tearing of the tissue.
Why are the eyes susceptible to laser damage? - correct-answer - The eye focuses
the laser onto the retina, amplifying the laser source.
,2|Page
What does the damage to the eye depend on? - correct-answer - It depends on
the power and wavelength of the beam.
Cornea - Far UV, 100-300nm, damages the cornea through photochemical effects.
Causes kerato-conjuctivitis.
Cornea - Far-IR - >1400nm Causes damage to the cornea through thermal damage
Cornea/lens - near-UV 300-400nm - absorbed by the lens, can cause cataracts.
Retina damage - Visible range/near IR, 400-1400 nm - Magnified by the eye so
lower levels can cause more damage. Causes thermal burns and bleeding
Extended source viewing of diffuse beams can lead to large scale/lower level
damage.
This is the level of laser radiation to which a person can be exposed without
hazardous effects or adverse changes in the eye/skin. - correct-answer - MPE
Maximum Permissible Exposure
Depends on Wavelength, Exposure Duration, Output, and exposure conditions.
J/cm2 - Pulse
, 3|Page
W/cm2 - Continuous
What is the difference between an extended source and a point source? - correct-
answer - It is based on the angular subtense. The further away a source is, the
more it is a point source. It focuses on a small spot of the retina. An extended
source is very close and the energy is spread across the retina.
How do we calculate the MPE? - correct-answer - There are values within the
ANSI standard, but in addition to that, we also need the anticipated exposure
value. They are different depending on the laser.
UV is all day
Visible is 0.25 sec(aversion response)
IR is 10 sec
Single Pulse is the pulse width
