Sun28November0333PM 33

Lasers are devices that produce or amplify a beam of narrow, convergent light with a well-defined wavelength within the electromagnetic spectrum. They are in widespread use in the theatre environment.

Which of the following options is most likely to prevent inadvertent injury to the eyes of theatre personnel?

(Please select 1 option)

Appointment of a laser protection supervisor Incorrect answer selected

Wearing polarised spectacles

Wearing laser protective goggles This is the correct answer

Using short bursts to reduce energy

Use of Class 1 laser devices

Explanation

The eye is most susceptible to damage.

Red and near-infrared light (400-1400 nm) can be focused up to 2×105 times greater intensity by the lens on to the retina. Most of the light is absorbed by melanin in the pigment epithelium just behind the photoreceptors and causes painless burns on the retina.

Infrared light (>1060 nm) is particularly dangerous as it will not elicit the protective blink reflex due to its invisibility.

Ultraviolet light (<400 nm) tends to be absorbed in the cornea and lens where it can produce burn injuries and cataracts at relatively low powers due to photochemical damage.

Laser protective goggles are designed to wrap around the eyes and prevent inadvertent direct and indirect exposure to the eyes of the wearer. These goggles need to absorb light specific to the laser being used at the time.

The appointment of a laser protection supervisor is recommended by the Department of Health in any clinical area in which lasers are used. Their role is in education and safe use of lasers, but their presence does not guarantee the absence of eye injury.

Use of Class 1 laser devices is incorrect since these would not be used in the theatre environment (medical lasers constitute a class 4 laser device).

Polarised spectacles may still admit laser light of the same polarity and in any case will not protect the peripheral visual field.

Using short bursts to reduce energy is incorrect, as short bursts of energy will still cause damage to the eye.

Answer Statistics

1

9%

2

4%

3

81%

4

4%

5

4%

Times answered: 235