Wednesday January 23, 2008

Overcoming Blog Inertia

The past two years have seen a great deal of change in my life, mostly centered on the arrival of my two children.  My son Timothy was born in 2005 and is now a very verbal two year old.  My daughter Kathryn was born just this November and has recently started to sleep through the night and smile.  There are so many cliche things to observe about becoming a parent, but they are so true.  Just when I think I could never be prouder, never be more tired or love them more; it turns out I am very wrong.

Monday January 10, 2005

LASIK Surgery

Two years ago, after a great deal of introspection and research, I decided to undergo LASIK surgery. I was 34 at the time and I had worn glasses for the vast majority of my life. My vision was 20/600, which means I could see at 20 feet what most people could see at 600 feet. I was very nearsighted. Without glasses I was unable to read anything further than about 5 inches from my face. Today, my vision is 20/20 in both eyes and the wonder of living life without glasses has not worn off.

Deciding On LASIK

My optometrist and I had spoken about LASIK and other vision correction surgeries for close to five years. At first his knowledge of the surgeries was superficial and his advice was to wait for a few years. Later he advised me to wait until my eyes settled down since most reputable surgeons require a candidate's prescription to be stable for two years. That was four years ago. I started to read up on the procedures available and talking to people who had the surgeries.

Most of the people I talked to had either PRK or LASIK surgeries. Most reported similar experiences, with LASIK seeming to have shorter recovery times. My optometrist started performing patient screening for a local franchise of The Laser Center and began learning a great deal about LASIK. I spent a great deal of time researching on the web; reading about the various positive and negative outcomes.

Two and half years ago, during a routine exam, my optometrist announced that my eyes had been stable for two years and he thought that I might be a good candidate for LASIK. He recommended The Laser Center in Austin, mostly due to the fact that only one surgeron was performing operations there and his success rate was extremely impressive. I contacted The Laser Center and scheduled a battery of test to determine if I was indeed a good candidate.

Elective Refractive Surgery

I arrived at The Laser Center armed with a checklist of questions and a paper entitled "Ten Reasons Why You Should Not Have Eye Surgery" ( or something very close ). I would be making a majority of my decision to trust my eyes to these people based on their reaction to my questions. They were delighted that I had brought so many questions with me and we proceeded to spend over an hour going through each question. The people at The Laser Center were very forth coming and provided as much historical data on previous surgeries' results as were available ( three years ). Before the first test to determine my suitability for surgery, I was ready to trust these people.

Next came a battery of tests, the purpose of most I forget. The one that stands out in my memory produced a topographic map of my eyes. It measured the thickness of my corneas and the amount of variation seemed alarming until I noticed the key. The apparant hills and valleys were absurdly small features on my corneas and completely normal. The final verdict, my corneas were thick enough to make me a good candidate for surgery. Thin corneas might tear during the procedure which increases the amount of time required to heal dramatically and increases the possibility of infection. Thick is definitely better.

LASIK or Maybe I Shouldn't Have Asked

Excerpted from http://www.fda.gov/cdrh/lasik:

LASIK stands for Laser-Assisted In Situ Keratomileusis and is a procedure that permanently changes the shape of the cornea, the clear covering of the front of the eye, using an excimer laser. A knife, called a microkeratome, is used to cut a flap in the cornea. A hinge is left at one end of this flap. The flap is folded back revealing the stroma, the middlesection of the cornea. Pulses from a computer-controlled laser vaporize a portion of the stroma and the flap is replaced.

You can imagine that reading about it and experiencing it might be two very different things. And you'd be right.

My surgery was scheduled for 11:15 am on January 9th. My wife and my optometrist accompanyed me to the clinic. My wife was going to drive me home afterwards and my optometrist just plain kicked ass (he's semi-retired now, otherwise I'd be shouting his name to the rooftops). We got there early and spent about 20 minutes in the (posh) waiting room before I was taken to prep. Preperation involved taking a sedative, a final check by the staff eye doctor and a brief visit from the surgeon. The surgeon was brief but positive and then I was lead into a darkened room to wait my turn. There was quiet classical music playing and three other people in the room mellowing out with their sedatives. One by one we lead away to the operating suite. My optometrist came and got me and it was my turn.

Blurred Impressions of Something Scary

The sedative administered before the procedure is important because three very unnatural things are about to happen. I entered the surgical suite and was situated on a padded table with a cluster of vaguely industrial equipment around the head. Vaguely because I wasn't wearing my glasses at the time. They don't waste alot of time, and in very short order they began prepping my eyes by placing numbing drops in them and cleaning around my eyes. Because blinking can be disruptive during the procedure, they then insert a lid speculum into your eye ( this is addition to taping your eyelids open ). That is the first unnatural thing. Next a suction cup is attached to your eye to hold the eye still while the microkeratome is used to cut a flap in the cornea. That is very unnatural, but didn't hurt. The flap is then lifted and folded over in preperation for the laser. At this point, my vision was very blurry and I was directed to look directly into a small red light directly above me ( the aperature for laser ). The laser used in my procedure incorporated an eye tracker which provides feedback to the laser and will also shut the laser off if your eye moves too far out of axis.

Staring at the red dot, the surgeon announced that the eye tracker had locked on and the laser would be firing it's preprogrammed sequence for some number of seconds. I don't recall the exact number, but it was less than 60 seconds. During that time, the laser buzzed but I didn't notice any visual artifacts. I was struggling to look at the red light, terrified that I'd wreck my eyes by moving at the wrong time. I also had a vague impression of a burnt smell, which of course was the ablated tissue from my eye. The third unnatural thing.

The surgeon counted down the last few seconds and the laser shut off. He then inspected the work done by the laser and spent a great deal of time folding over and smoothing out the flap in my corena.

The first eye ( the right ) was done.

I was shaking like I was caught in a blizzard without a jacket. I had no idea how I would endure the left eye. The discomfort of the ligature and the fear of loosing my sight due to moving during the procedure were overpowering.

And then the coolest thing happened. My optometrist, who had accompanied me into the suite and observed everything so far, reached out and patted my foot and murmured a few words of encouragement. That's all. I felt a sense of relief that just flooded me. I can't explain it since I was defintely under the influence of the sedative, but I stopped shaking as much and the team went to work on my left eye. While uncomfortable, the left eye was no where near the ordeal that the right eye was.

Less than ten minutes in the suite and I was being led out. My doctor and the staff doctor examined my cornea flaps and gave care directions to my wife since I was still pretty shook up. I had antibiotic eye drops and steroid drops and lubricant drops and a pair of clear eye shields that I would need to wear for weeks ( to prevent me from touching or rubbing my eyes and disrupting the healing of the flaps in my corneas ).

On the car ride home, I was blurrily reading the roadside signs.

Without glasses.

Recovery

The first two weeks I was certain that I'd had a bad outcome and my anxiety during the procedure was the cause. But in reality my eyes were healing and my expectations hadn't been realistic. My vision was blurry but already far better than it had been without glasses. After two weeks, my vision was 20/20 in the right eye and 20/15 in the left. I would have good seeing days and bad seeing days, but I think those might have been related to the muscles around my eyes re-learning a lifetime of movement to accomodate my new accuity. My doctor was unable to explain the descrepency between my right and left eyes. We think the difference might have been induced by my anxiety during the right eye, but it's only a theory. We recommended back to the clinic that they review the amount and type of sedative given since I might not have received enough.

The two biggest post-procedure complaints most people have are dry eyes and haloing at night. The dry eyes stems from the nerves in the cornea which are severed when the flap is cut. Those nerves provide feedback when the eye became dry and take time to grow back. For the first six months afterwards I used eye lubrication three or more times a day. Two years later I don't have any need for supplimental lubrication.

Haloing ( or flaring ) at night happens when viewing a bright light ( such as oncoming headlights in traffic ). For me, the haloing is no worse than what I had experienced with contacts. There is an interesting retouched photos on Surgical Eyes which attempt to show what it's like to experience haloing. The photos are not representative of how I see at night; the halos I see are much less pronounced.

Two Years Later

It's been just over two years and I could not be happier. I can wear cheap $5 sunglasses and not worry if I loose them. I can SCUBA dive without worring about loosing contacts during a dive. My pistol and rifle shooting improved. I can read the clock across the room when I wake up in the morning. Practically every aspect of my life improved, including my self-esteem.

As I grow older I'm told I will become farsighted and will require reading glasses. Until then I should enjoy 30 or more years of good vision. I think I can live with that.

-ejo

(2005-01-10 14:02:02.0) Permalink Comments [1]

Friday August 13, 2004

Second Wind

Dear Diary, been busy.

The Good

This weekend I'm diving in Lake Travis to finish up my PADI open water diver refresher course. I am not an experienced diver ( 7 dives with about 2 hours of bottom time ), but I looking forward to the check out dives and starting again. My friend and cow-orker Roy and his wife have just recently completed the PADI open water diver course and are taking the advanced open water course this weekend.

I'm almost all kitted out, just missing a regulator/first stage and a dive computer. I think I've made up my mind on both, but I'm easily swayed. For regulators, I've been considering the Aeris Sport Pro, the Atomic Z1, and the Mares Abyss. All are solid regs, but lacking an opportunity to try them all I have to fall back on recommendations and reviews. So far I'm leaning towards the Aeris Sport Pro.

The dive computer I've decided on is an Aeris Atmos Elite, which is a hose-less wrist mounted computer with a tank-mounted transmitter ( not a radio apparantly, but something that can wirelessly transmit tank data to the computer ). I considered other air-integrated comptuers as well as other wrist computers. The Aeris appears to give the biggest bang for the buck. The dive instructor I'll be with this weekend uses an Elite, so I'll get a chance to play with it (maybe). The wrist mount seems to be the most conservative place you could put your expensive computer, as well as putting it in a position where it can be checked more often. ( You can always find your wrist, sometimes it's hard to find your console if it's not clipped in. ). It's a lot of cash for an initial purchase, but I'm hoping to avoid having to re-buy gear in the future by going alittle overboard to begin with.

I transitioned from Redhat 7.1 (ancient) to Fedora Core 2 on my machine at home, so I had to spend alot of time migrating services that had I had setup long ago and forgot about. DNS and mail via postfix were the first things to be setup, followed by postfix and spamassassin. I only just now got around to setting up the cron jobs which control all the X-10 lighting around the house, and it feels good to not have to turn lights on and off now. I use a X10 Firecracker serial port dongle to send X10 commands wirelessly to a wall-plug mounted receiver. The Firecracker is pretty neat, but uni-directional so you can't query device status. I just ordered a bi-directional dongle from X10.com, but haven't had a chance to play with it yet.

My wife recently got our new fish tank set up, so I thought it would be convenient to plug the tank light into an X10 appliance module. After all, that worked pretty well with the last tank. Wrong. It turns out that run-of-the-mill X10 appliance modules have a feature called "local control" which monitors the draw of the plugged in device somehow (I'm not an electrical engineer and don't pretend to be ) to see if you are trying to turn it on when the module is off. When it sees a draw or whatever, it obliges you and turns power on. This is all well and good for regular appliances, but florescent lights are a whole different animal. You can turn them on and then turn them off, but after a 2 second pause they turn right back on again. It's like having a very annoying ghost. Well, on www.smarthome.com they have a convenient FAQ which addresses just this question. On the particular module I have, you can disable the local control circuitry by opening the module and cutting a trace on the backside of a small circuit board. I gave it a try, and what do you know, it worked. Of course I managed to damage my thumb while doing this, but I like to think that spilling my own blood somehow enhanced the probability that it would work on the first try.

The Bad

Luckily, this section is sparse. My dog Sam is still limping since getting accidently trampled over the 4th of July, but seems to be getting slowly better. She has always had trouble with her right rear leg, but she's not getting any younger and doesn't bounce back quite as fast. She is mostly a three-legged dog now, but every day she seems to be putting alittle more weight on it.

I cut the dickens out of my thumb cutting the aforementioned X10 circuit board trace. I knew I was tired, but I wanted to see if it would work. As I was digging into the board with my pocket knife, I remember thinking to myself "If the blade slips, I'm gonna cut the snot out of my thumb." And then the blade slipped. So the moral of this story is: If you are tired and it involves knives, wait until you aren't tired. And if you think you are going to cut yourself, you probably will. My previous serious injury with a chef knife started with me being tired and thinking that I was about to cut myself. Well, it seemed serious to me; the finger nail eventually grew back.

The Ugly

I can't put the instruction tracing thing away quite yet. DTrace is slower at instruction tracing than my user trap handler tracing tool, but the amount of effort that I had to invest using DTrace was significantly less. Since the DTrace pid provider allows you to specify probes by offsets into functions (rather than by pattern matching instructions or mnemonics), I thought it might be fun to write a perl script which takes a victim object and generates a DTrace script with probes for just the control transfer instructions (CTIs). It's not quite done yet, since I haven't written any perl in quite some time and have forgotten alot more than I expected :). Firing a DTrace probe every 5th instruction on average should go a long way towards reducing the DTrace impact on the program under test. Whether it's interesting to anybody is a whole 'nother question!

-ejo

(2004-08-13 10:58:40.0) Permalink Comments [1]

Thursday July 15, 2004

First Post!!! I'm so pumped!

I'm blogging like all the other cool kids!

I'm Erik, I live and work in Austin Texas. I am a serious UNIX nerd, and I geek out on observability issues. I worked for IBM for 8 or so years; first as a co-op student, then a contractor and finally a regular employee. I worked with AIX on multiple platforms during my time there ( PS/2, RS/6000 and the RT briefly ). I joined Sun in August of 1999 .

Things I Claim to Know Something About

• Solaris Kernel and Virtual Memory
• SPARCv9 User Trap Handling
• Application Linking and Loading (ld.so)
• ELF File Format
• UNIX C Development Environment
• emacs and emacs lisp
• SPARC Assembly
• X11/Xlib/Xt and Motif Application Development
• TCP/IP Application Development
• Pthread and Thread Application Development
• Kstat Observability Development
• Audit Library Development
• MDB Debugger Command (dcmd) Development
• Solaris Device Driver and Loadable Module Development
• Kernel and User-land Application Debugging
• General UNIX Hackery

When I'm not pounding on a keyboard, I like:

• Competitive Pistol Shooting
• Playing SOCOM 2 online, my nickname is "Jöhnny".
• Slowly re-modeling my house.
• Assembling PCs from random parts.
• Napping with my dogs ( Sam and Sid ).

Wow this is harder than I thought, writing all this stuff. Maybe I'm not cut out for blogging!

-ejo

(2004-07-15 14:28:27.0) Permalink Comments [2]