Wednesday, September 14, 2011
THE CLOSE RISK OF EYESIGHT LOSS WEEK 54 QUOTE 54
"An 11-year-old boy has permanent eye damage from the beam of a green laser pointer that was bought as a toy.
It burned his retina - the light-sensitive back of the eye - leaving a 1.5mm scar and increasing his risk of developing central-vision blindness.
His eye specialist, Dr Diane Sharp, and his mother want the Government to follow other countries and restrict access to high-powered laser pointers.
Regulations are being developed, but laser sales are still unrestricted.
Their call follows a demand from the Airline Pilot's Association for regulatory action.
The association is concerned at the number of cases of laser pointers being shone at planes in the air - at least 17 this year - which could distract or dazzle a pilot at night, leading to a crash.
The devices have also been used against police, sports stars and car drivers.
They are intended for use as lecture pointers or for pointing out the direction of stars, but often they are sold as toys or gimmicks and are dangerously and unnecessarily powerful.
The 11-year-old, whose family requested anonymity, bought his 200milliwatt laser pointer for $15 during a family holiday in Thailand in January.
His mother said that in June, he played with the pen-shaped device in his bedroom with a friend on a sleep-over.
Afterwards, he had a "fuzzy blob" in his vision.
His mother later learned he had lasered his eye when he shone the pointer in a mirror and was momentarily hit by the reflection.
She said the family knew not to shine the light directly into the eyes, but did not know of the risk in reflecting the beam.
The boy has lost some visual sharpness in his right eye, reducing its reading level on the eye-testing chart by three print sizes, but his overall vision is not greatly affected because his left eye was not lasered.
"We are going to be extra protective of his vision because he is slightly compromised," his mother said.
"I feel bad because (the pointer) just seemed like a fun, groovy thing to buy. It did have this warning on it, but we had to get the magnifying glass out subsequently to see it : 'Danger, radiation, avoid direct eye exposure.'"
"There needs to be raised public awareness about the easy availability of them and the potential damage that can happen so quickly."
Dr Sharp said: "The voluntary standards are not adequate for this device. Consumers do not understand the classification system. A class-three 200mW green laser is extremely dangerous."
Laser pointers can be used for :
* Lecture and presentations. The National Radiation Laboratory says 1 milliwatt is powerful enough.
* Amateur astronomy, for pointing towards stars and aiming telescopes. Laboratory says 50mW is maximum needed.
Unsafe uses :
* Don't give any laser pointer to a child as a toy.
* Don't aim one at a person, especially the eyes, or at a mirror."
"BOY'S HIGH-RISK LASER TOY LEAVES HIM WITH SIGHT LOSS" by Martin Johnston. nzherald.co.nz.
To understand a little about how light from a laser works, I found an excellent article on line from Scientific American, "Can a Pocket Laser Damage the Eye?" It compared a laser light with the light from a light bulb.
A light bulb sends light out in all directions and we see only a small amount of that light at one time. A laser however, sends out light in one small beam, so if the laser is aimed at an eye, the eye is receiving all the laser's energy.
The light of a light bulb is of different or varied wavelengths, but the laser is "a pure tone, only one wavelength. The coherent light will be more damaging."
"Because of the unique features of laser light, it is magnified by 100,000 times as it passes through the eye. The light passes to the back part of the eye, the retina, which is where we perceive vision."
Scientific American made similar recommendations to the article above, with the addition of "DO NOT look at a beam from a laser through a microscope or binoculars."
In the streets of Auckland city at the Rugby World Cup celebrations, one of my sons saw children with laser 'toys', shining them into people's faces. The danger when laser pointers are mishandled, definitely needs to be more prominently known!
Another source of damage to eyesight, can come from the more readily used, digital camera flash.
Recently the 18-year-old daughter of a friend, suffered damage to her eye after photographing herself at arms length in the dark, with her digital camera. As she took the shot, she held the camera to the side. The camera possibly focused on the wall behind her, the flash therefore giving a more generous quantity of flash to light the distant wall, in comparison to if it had focused on the girl herself.
Dr Diane Sharp, who is a part of this case, along with fellow collegues, found the degree of damage to the girl's retina, surprising. The camera flash was tested to check if it had malfunctioned and was found to have an acceptable intensity.
Online I researched camera companies to see if they carried any warnings in their information section about dangers with camera flash ~
Kodak's warning was detailed and clear especially in relation to photographing children, recommending no closer than 1.5 metres.
Nikon and Olympus likewise expressed caution when photographing infants, recommending no closer than 1 metre.
Pentax said, "Do not use flash near anyone's eyes ..... be particularly careful with flash around infants."
However online "Peano's forum article "About Eye Damage from Flash" in February 2007, said "....to produce .... permanent damage, a focused intense light must be held in one location on the retina for a time several magnitudes greater than the duration of a camera flash .... flash as a main light in dim light conditions may produce a temporary reduction in vision but no permanent damage. Flash on nocturnal subjects during nighttime should be used sparingly due to brief impairment of vision. ..... Hypothetically, if scientific information indicated that flash photography under normal use, produced permanent retinal damage, it would trigger additional rules and regulations."
Tim Solley in "Will Flash Damage Babies' Sensitive Young Eyes?", came to the same conclusion as Peano's forum. Having done a thorough Google search on material up to September 2007, Solley said that camera flash cannot permanently harm the eyesight of babies.
These two comments and others like them on Google, are probably completely accurate when photography is practiced within the norms of the pre-'bebo' years.
Digital cameras became more common around 2003-2004. But it was probably in July 2005 when the website 'bebo' was launched, that the phenomenon of photographing oneself at such close range, actually began.
Searching through Google from 2011, 2010, 2008 and 2006, the number of handheld self photographed images diminishes sharply with each year, until in 2004 I could only find one recorded image taken in this method.
A handheld self photographed shot, is CERTAINLY less than 1 metre distance from camera to subject face, and in some cases would barely be 50cm in distance. This is well below camera makers recommendations, putting this style of photography out of the category Peano's forum described as "flash photography under normal use".
With increasing numbers of people using cameras in this manner, POSSIBLY the effects and dangers thought previously not to be possible, need to be researched and reassessed. Eye specialists are alert and have begun research, and professionals in the camera industry should follow, re evaluating their warning information with flash usage.
If an eye is damaged by a camera flash, the other eye works toward compensating for it, over the following days. This can give an injured person, a false idea that healing has occurred. This is why it could be hard for parents to determine if a small child has eye damage or not.
How does all this affect someone using flash on their camera?
* Do you really need a flash? If not, turn it off. I recently watched a mum photographing her
preschooler in doors. She took dozens of shots all on flash, at a distance of less than a metre.
* When you do need to use flash, get children to look to the side of the camera before the shot, NOT
at the flash. (my friend suggested this and the next 2 suggestions - thanks C)
* Restrict photographing in the dark. Eyes fully dilate in the dark and so are fully open to allow the
maximum amount of flash in - this is dangerous.
* If photographing in dark conditions, be aware and careful of where you aim the camera. A camera
flash senses how much light is needed to illuminate the object in focus. If it is directed at a distant
wall, you over flash yourself.
My friend's daughter has been recovering well since her accident two months ago.
THISWEEKWITHTHEKIDS ~ If your kids take flash photographs, maybe you need to share this information with them.
The dangerous risks with laser pointers, needs to be circulated and made public to parents and children alike.