Lasers In Aviation Flashcards
Issues for pilots from lasers
Distraction
Temporary visual impairment
Concern for eye injury
LASER stands for
Light Amplification Stimulated Emission Radiation
What determines is an eye injury occurs from laser
Reduction in energy: distance, spread
Attenuation of energy: atm/weather, cockpit window
Most event are brief: eye blink response, flight profile, Jitter
Types of laser
Solid state lasers: ruby and neodymium YAG
Semiconductor laser: Gallium arsenide
Gas lasers: argon, CO2, Excimer
Liquid lasers
Characteristic of LASER light
High intensity Narrow wavelength Narrow beam Collimated In-phase, brightness Energy emission can be continuous wave or pulsed
Classes of laser light
Class 1: safe
Class 2: need eye protection, causes blink reflex
Class 3: cause eye injury but no skin injury for R but B can cause skin injury
Class 4:eye and skin burns very bad
what are military laser uses
Range finding target designation training maintenance weapons - on ARH and Jets, Damage, enemy optical sensors, antipersonnel damage to eyes and tissues
Laser on the ARH tiger
Class 4 for targeting and range finding Recognition at 7km Detection up to 80km ID to 3.8 km
Issues with laser in aviation
Distraction
glare
flash
What is the damage laser can do
Photochemical - actinic - UV and shorter visible wavelengths - Superficial Corneal burns Thermal- photocoagulation - low power visible and IR CW LASER - Deep corneal burns and retinal burns Thermo-acoustic damage - high-power lasers - thermal burns to skin - tissue disruption (thermo-acoustic damage)
what wave lengths effect what part of the eyes
Green UV B C 100-320 damage cornea green UV A 320-400 damage cornea and lens Yellow and IRA 400-1400 retina IRB 1500-1800 all but retina IRC 3000-1000000 cornea
Limitation of blink response (aversion)
only works for visible
Blink and turn head ~0.25 sec
protection for class 1,2,3a
Class 4 just goes through eye lids
characteristic of cornea damage
UV - B, UV - C Damage due to photochemical reaction Latency period - hours painful usually heal within a few days may have reduced vision
IR
Immediate burns to all layers
permanent scarring of cornea
High energy denatures protein, globe perforation, loss of eye
Characteristic of retinal damage
Hemorrhage and burns on retina IR B tears and haemorrhages direct damage to fovea gravitation of blood toxic reaction to Hb damage to nerves
Characteristic of skin damage
IR and UV can tolerate more exposure than eyes acute burns ulceration damage to underlaying organs
How to test vision when suspected exposure to laser
HX: eg pain, grittiness, afterimages, blurred/reduced/loss of vision, photophobia
Ex: hyperaemia, keratitis, corneal burn, haemorrhage, retinal burns, tears, globe disruption
Amsler grid
Tx for the following
Keratitis, corneal burns
retinal injury
Globe rupture
Keratitis, corneal burns
- topical abc, cover eye, analgesia
Retinal injury: urgent referral
Globe rupture: plastic eye shield, no eye drops or ointments, IV Abx, urgent referral
Ophthalmology referral if clinical concerns, severe pain, any visual field loss
when to return to flying
if no external ocular damage, pain or threat of ocular cx
best corrected VA 6/6 in better eye and 6/12 in other
Consider specialist roles
- aircrew corrected VA 6/6
what are the requirement for personnel that are required to work with Class 3 or 4 lasers
Pre-employment
post employment
annual health assessment
Ophthalmologist - retinal photography
recommendation for aircrew if flying and laser
Look away and shield eye If vision affected then hand over or engage autopilot tell everyone fill in ASOR avoid rubbing eyes visual aids in nav bag to test sight
What is the main issue with laser
distraction and glare
