Slashdot Mirror
Surgery with Femtosecond Lasers
An anonymous reader writes "Science Daily has an article on femtosecond lasers, which emit pulses of light that are a billion times shorter than an electronic camera flash and how they are currently being used in LASIK procedures."
I write in pure HTML - why would anyone want to do otherwise? Oh hang on - wrong thread!
not really, more like a few milliseconds
I guess we should really come up with some standard system for measurement in news articles, the JI (Journalist Idiots) System of measurement.
Time - camera flashs
Small physical size - human hairs
Large information - Library of congresses
Meteor size - VW Bugs
Any more?
I've had enough abrasive sigs. Kittens are cute and fuzzy.
Height: Empire state buildings. eg. if you stacked a quadrillion pennies they would be X times the height of the Empire State building.
Height 2: Earth-Moon. eg. if you stacked a quadrillion cases of beer, they would reach X% of the way from the Earth to the Moon.
Accuracy: Amazing Hole in One. eg. NASA's space probe reached Saturn only 4 microseconds late. That's like sinking a Hole in One from X billion miles.
Length: Earth circumferences. eg. If you laid all the fiber in the world end-to-end it would stretch around the globe X dozen times.
Volume: Olympic Swimming Pools. eg. a million cases of beer would fill X Olympic Swimming Pools.
Then, there's the famous nanoseconds that Grace Hopper used to pass out. They were little pieces of wire an inch(?) long that represented the distance light travels in 1 nanosecond.
If tits were wings it'd be flying around.
Light travels about a foot per nanosecond.
They would get a lot more done if they left the laser on longer.
Burner speed: older burners. "This fast burner is the equivalent of 40 burners!" Used mainly by the RIAA.
if the answer isn't violence, neither is your silence / freedom of expression doesn't make it alright
I had LASIK surgery on both eyes in 1997. I had -6.5 (diopters ?) in both eyes (very short sighted) and came out of the operation with 40/20 vision (better than 20/20) in both eyes.
A microkeratome (razor) was used to create the "flap". They told me that it was this device that was the "weak" link in the entire procedure as it could get stuck or could cut slightly wrong, as mentioned in the article. As the surgery is done while awake (both patient and surgeon), I was relieved when told that the microkeratome had cut successfully. I was lucky and have no complaints: I had to use several eye drops for 3 months during which time my vision was *slightly* hazy (at night) but nothing after that.
One of my eyes has become slightly astigmatic (natural process) and I am considering another LASIK procedure as it is now several generations on from my previous surgery. Good to know that the microkeratome is possibly on the way out.
"Those who don't believe in magic will never find it." - Roald Dahl
...right here(scroll down to the bottom for mpeg)[warning! not for the squeamish!].
- "Hear that?! The percolations are imminent! Cease your ingress!"
Almost everyone I've ever talked with who's gotten laser eye surgury has been disappointed with the results.
As someone who had LASIK, I can tell you that I am ecstatic with the results. I have essentially 20/20 vision in both eyes and do not need to wear glasses for anything. That makes it worth every penny. Yes my eyes were a bit dry afterwards, but that had as much to do with staring at computer screens for 8+ hours daily than the surgery. When I was off work my eyes were fine.
Now that said, it isn't for everyone. If you are comfortable with glasses and don't have a compelling reason to have the surgery besides annoyance, you might not want it. It is a risk after all. In my case I'm an athlete (yes they do exist on slashdot) so it was valuable to me to not have to wear glasses.
Anyway I'm thrilled with the results but recommend that anyone thinking of getting the surgery research it very carefully. It's not something to be taken lightly and I'm glad I didn't.