Go Back   IceInSpace > General Astronomy > General Chat
Register FAQ Calendar Today's Posts Search

Reply
 
Thread Tools Rate Thread
  #1  
Old 15-09-2007, 08:59 PM
WadeH's Avatar
WadeH (Wade)
WadeH

WadeH is offline
 
Join Date: May 2006
Location: Currajong/Townsville Qld
Posts: 426
Exclamation Laser Injury Results

I know this is long winded but found it both interesting and important considering all the negative press lately about green lasers.
It is on Bintels website through the link to the Nightsky newsletter (Sept)
https://www.bintelshop.com.au/welcome.htm
From what I understand the Mayo Clinic is very reputable and can be trusted.

LASER POINTERS AND THE
HUMAN EYE
A Clinicopathologic Study
Dennis M. Robertson, MD; Tock H.
Lim, FRCS(Ed); Diva R. Salomao,
MD; Thomas P. Link, CRA; RobinL. Rowe, COT; Jay W. McLaren,
PhD
We report the absence of photic retinal injury after exposing the retina
to light from class 3A laser pointers for durations of up to 15 minutes.
Three patients with uveal melanomas were scheduled to have an
enucleation. Each agreed to have his or her retina exposed to laser light
from a class 3A laser pointer prior to enucleation. Continuous exposure
was directed to the fovea for 1 minute, to the retina 5° below fixation
for 5 minutes, and to the retina 5° above fixation for 15 minutes.
Ophthalmoscopic evaluation of the cornea, lens, and retina and
fluorescein angiographic studies of the retina were conducted before, 24
hours after, and 11 days after laser exposure in the first case; before and
86 hours after exposure in the second case; and before, 96 hours after, and
15 days after exposure in the third case. Other than transient afterimages
that lasted only a few minutes, we were unable to document any
functional, ophthalmoscopic, fluorescein angiographic, or
histologic evidence of damage to any structures of the eyes. Transmission
electron microscopic studies of retinal sites targeted by the laser
pointers in the second and third cases revealed ultrastructural abnormalities
in the outer retina and the pigment epithelium that were similar to
abnormalities seen in the retina approximately 8 mm away from the
targeted sites. The risk to the human eye from transient exposure to light
from commercially available class 3A laser pointers having powers of
1, 2, and 5 mW seems negligible.
From the Department of Ophthalmology,
Mayo Clinic, Mayo Foundation, and Mayo
Medical School, Rochester, Minn.
Reply With Quote
  #2  
Old 16-09-2007, 12:07 AM
citivolus's Avatar
citivolus (Ric)
Refracted

citivolus is offline
 
Join Date: Sep 2007
Location: Carindale
Posts: 1,178
Personally I suspect that the issue is just the brief distraction caused by the flash of a temporary alignment with the beam, and that there is no lasting impact from such short term exposure. The latest Brisbane info stated that the laser had "tracked the flight across the city", which I find somewhat hard to believe. Most people have a hard enough time hitting their own television with a remote control that has a 15-30 degree field, not to mention hitting an aircraft with a laser that has a 1.4 miliradian beam divergence. For perspective, at 30Km distance, this example laser would have a spot size roughly the same size as the aircraft. At 10Km, the spot size would only be 14 metres. That requires incredible aiming skill by the user, even if the beam is visible.

The whole problem is self generated, since the people doing it are only doing it because they have heard it is dangerous. Train pilots to handle distractions, tell the media to stop hyping this non-news story, and the problem will go away. We've had laser pointers for what, 15 years? It hasn't been an issue until now.

I'm more worried about lightning hitting my plane, runway debris, and bird strikes, thanks.
Reply With Quote
  #3  
Old 16-09-2007, 01:15 AM
dwyman
Registered User

dwyman is offline
 
Join Date: Feb 2005
Location: Oshkosh, Wisconsin USA
Posts: 122
I do believe that report is about red laser pointers, not the green ones.
Reply With Quote
  #4  
Old 16-09-2007, 02:05 AM
Ingo
Registered User

Ingo is offline
 
Join Date: Apr 2007
Location: Albany, NY
Posts: 559
3A laser pointers won't do much damage unless there's long exposures into the eye. Your blink reflex is quick enough to stop any damage. 5mW to around 15mW should be the limit on which you could be safe without eye protection. Anything above and your blink reflex isn't quick enough.
Reply With Quote
  #5  
Old 16-09-2007, 03:11 PM
xelasnave's Avatar
xelasnave
Gravity does not Suck

xelasnave is offline
 
Join Date: Mar 2005
Location: Tabulam
Posts: 17,003
As with most things all we need is a committee and new laws..
I have wondered how the heck one could line up a plane even for a casual "hit" and the prospect of tracking with such a beam would require sophisticated tracking gear... still a committee will get to the bottom of it... and of course a tax on them that should do it.
alex
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 07:53 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement