Monday, January 27, 2014

LASIK


I've worn glasses for most of my life. I'm nearsighted and I've got moderate astigmatism as well. I think I got my first pair at around 8 or 9 years of age, when my teacher realized I couldn't see the text on the blackboard. I've been completely dependent on glasses ever since. This has never bothered me — glasses work well and they add a bit of character to my face.

Portrait
Me and my current pair of glasses.

But a few years ago I started developing presbyopia, so I've been using bifocals, glasses that let you see far through the upper part, and focus close through the lower. Or that's the theory. I need to correct my astigmatism as well, so the lens design becomes a compromise. I really only see well along a narrow vertical strip in the visual field. I have to move my head constantly to read or use a computer.

In practice I need two pairs of glasses, one pair for seeing far, and a second pair that give me a wide field of view close up. Two pairs of glasses to fumble with on the train and at work yet still never seeing really well - now that is a bother. A few weeks ago, an acquaintance blogged about his LASIK surgery here in Japan, and that prompted me to take a look for myself.


With LASIK you cut open a flap in the surface layer of the cornea, then reshape the cornea itself with a laser1. At first they only corrected nearsightedness. Then they started to correct astigmatism but only the overall shape, not smaller irregularities. As a result people would often get minor side effects such as low contrast and glare at night. No real problem compared to bad eyesight, but I was happy with glasses so I saw no need to rush.

But now I'm no longer happy. It's now possible to do a much more precise correction than earlier. With the latest methods you map the light paths through the eye, then calculate how to reshape the cornea to correct not just the major errors but smaller irregularities too. That should reduce the risk of visual side effects.


This weekend I went to the Kobe Kanagawa clinic in Sannomiya for an eye exam. The exam took over an hour but was mostly a sequence of "put your chin here, look into this machine. Don't blink. Great!", as various machines measured my visual errors, pupil size, corneal thickness, intraocular pressure and other parameters. I also got a careful manual eye test and a medical eye exam.

My vision problems are moderate, I've got above average corneal thickness and no other eye-related issues. LASIK surgery should suit me fine, and my cornea is thick enough to do a second corrective surgery if the first one isn't perfect.

I will still need glasses when reading or when I use a computer or tablet2. But it would be simple reading glasses, with no need to switch between pairs. And I could go completely without glasses when going out for walks, taking pictures, or when swimming, snorkeling or skiing.


I have a date for surgery next month. The actual procedure takes only ten minutes or so, but I start eye drops three days beforehand, and have follow-up exams and wear protective glasses for a week afterwards. The vision will apparently not stabilize fully for a month or longer, so I will need a temporary pair of reading glasses until I can fit new lenses to my regular pairs.

A bit nervous, but I'm looking forward to it.


#1 The cornea — the hard, transparent cover in front of the pupil — is really the main lens of the eye, and the one that does most of the focusing. The soft lens behind the pupil that we think of as "the" lens is much weaker, and there only to adjust the focus.

#2 Yes, pretty much all day, every day. I know, I know...


9 comments:

Jordi Pujol said...

Worth it, at least you won't have to deal with the annoying pair changes.

I am with your first paragraph situation; alright, but being near 20 the opposite would be odd.

Every once in a while I think about it, but at the moment it's something quite expensive and with ordinary glasses I'm fine.
And if the process is getting better, no need to rush.

Hope you enjoy the new ASPH Summicron right there! ;)

Jan Moren said...

Hi Jordi,

In my current circumstances I would perhaps do this now even if I were in my 20s and my glasses were fine. There's clearly been a good deal of progress on the technology, and the results promise to be much better than just a decade ago.

But of course my "current circumstances" include a decent salary and years of savings; in my 20s I would never have been able to afford this, good idea or not :)

Jordi Pujol said...

Your point is spot on. As with you back then, the circumstances aren't there yet... And given many expectations of our generation not being as well off due to the turmoil, it might take more time.

So it gets postponed to a backlog of "things to do after finishing university".

Right there with a SE Asia tour with my father, many photography things, etc. :)

For what I've seen, numerous clinics here quote about 800€ per eye. Not that bad, but it's quite some money for a student (or the hobbies).

There was however a special surgery done by one of them that triples that quote. I think it's that it was less intrusive on the cornea and suited to more complicated cases.

Richard said...

Hope it works out well! Amazing what can be done these days. I remember first seeing videos of laser eye surgery at the Science Museum in London when I was a few years old. Freaked me out a bit. But it was also exciting, because lasers.

Jan Moren said...

Richard, I know the laser angle is still part of the draw for me today :) It just wouldn't be as cool if they used a knife or something, even if the results were the same.

Jordi Pujol said...

Richard's mention to videos sparked my curiousity and went on to see a couple of LASIK procedure videos.

Amazing procedure and shows how advanced our technology is and will be.

Jan Moren said...

Jordi, I looked at some videos earlier. Let's just say I didn't want to see people treating eyes like that - swabbing them, squishing them, poking them with pointy tools - right before I'm due to undergo the same thing...

Jon Allen said...

Very interesting thanks for posting. I am in a very similar situation, though my latest pair of glasses I just managed to get away with not being bifocal. I've considered laser surgery every couple of years for at least 20 years now, but never taken the plunge. Maybe next time I new vision prescription I will consider it again

Jan Moren said...

Jon, if you could "just get away with" not having bifocals, you would probably find bifocals more comfortable already.

When I got them, I realized I had waited at least a year or two too long already. I'd slowly developed headaches and tired eyes without realizing it, and when I finally got bifocals it almost completely disappeared. It was night and day.