LASIK Part Two

The post surgical advice the laser specialists give you is to go home and sleep but I found this rather impossible to do. My eyes felt like I'd been standing in the middle of a circle of smokers and I couldn't rub them, they also ached and were very bloodshot, they looked like I'd pulled a all night drinking session but didn't feel tired so I couldn't sleep.

My vision was hazy and it was difficult to keep my eyes open because the light hurt a little so in the end I plugged in headphones and listened to LBC radio over the internet. This worked well because it's a chat station so it was easy to mentally get involved with the discussion and keep my eyes closed. About 9pm that evening my appetite started to come back so krys (my wife) very kindly bought Pizza.

It must have been something of a surreal sight, sitting there on the bed, curtains drawn, lights out, munching pizza listening to radio over the internet :) The blurb says that 2-4 hours after surgery your eyes will feel better. Mine took 5 hours but the change at 5 hours was remarkable, I could see, my eyes ached a little but as long as I avoided bright light I was fine.

For the first seven nights after eye surgery they give you a funky eye mask to wear. This is designed to stop you accidentally poking or rubbing your eyes. It takes a few goes to get it sitting comfortably but it works well and that evening I had a good nights sleep even in goggles!

Another thing to note, for the first 7 days you are on a cocktail of eyedrops, anti-biotic, anti-inflammatory and artificial tears. I must admit that I never thought I'd need the artificial tears as my eyes used to stream at the drop of the hat but since laser surgery that's pretty much stopped.

The next day I was able to get up, use the computer for a little bit and walk around with near perfect vision. I was impressed, after 20 minutes of using the computer I had to walk away though as my eyes were still a bit light sensitive. It was at this point I noticed something wrong, my distance vision was perfect but my close up vision wasn't right.
My right eye was fine but my left eye hard marked double-vision which caused me slight panic until Krys very kindly slapped me on the head and told me to calm down as it wasn't even 24 hours post surgery. Also, I had a follow up appointment that day so it was best to see what they had to say.

That afternoon I was able to walk from home to the local optical express (about a km) although I needed sunglasses even though it was cloudy. My eyes were still very light sensitive.
At optical express I was seen by the same person who did the pre-op assessment and I have to say that throughout the whole process she has been awesome.
So, This first post op assessment was quite positive with the exception of inflammation and dryness. The inflammation being caused when I squinted just before they created the flap. I was told to use more of the Pred Forte (anti-inflammatory agent) in the left eye only and to use a lot more of the blink drops (artificial tears). The good news was that there were no striae (bubbles in the cornea due to flap movement) and an eye test showed that my right eye was 20/20 whilst my left was 20/30 - not perfect but a lot better than before surgery.

The next appointment was supposed to be a week later but was set for the end of the week as they wanted to check on the eye dryness.

Anyway, rather than go on about each visit to the optician I'll summarise it quickly. In two months I've been seen 4 times with a 5th appointment due in another three weeks or so. One appointment was cancelled due to the optometrist getting caught up on the M20 after a very nasty accident but it was rescheduled for the next day.

The second visit showed that the anti-inflammatory had worked but I still had slight ghosting in the left eye. This was due to excessive dryness which was still causing problems so I was given some gel to use of a night to help keep my eyes moist.

2 more check-ups on and I'm finding that my eyes are still light sensitive but they always were prior to surgery so that's not a big surprise, they are not as dry as they were but still dry so I make sure I've got the artificial tears on me at all times. The blurb says that your vision will continue to improve and it's true. 8 weeks on and I suspect my left eye is 20/20 now so I'm looking forward to a follow up eye test to see if it's true. The follow up care from Optical Express has been second to none. The apologies (and free cup of tea) when the optometrist was stuck in traffic was lovely and they have been more than generous with additional blink drops and other sorts of eye gel supplies.

The two hardest bits for me were finding something to do the evening after surgery and not being able to get my face wet in the shower or wash my eyes in the sink for the first seven days.
Your eyes and eyelashes need cleaning after the eyedrops because they can be messy, the way you have to do it is with a face cloth and kettle boiled water (let it cool down obviously!) then you VERY CAREFULLY dab your eyes and lashes - It works but it is cumbersome. The reason for this is simply because you can't risk any sort of bacteria taking hold on the eye or worse under the cornea.

So that's about it for my experiences. The first evening was hard going, the next day better and since then my vision has been perfect in my right and near my perfect in my left and improving. Not having glasses has given me a whole new way of looking at the word and I do mean that literally, I no longer have the frames of the glasses in the way of my vision, my night vision and peripheral vision are incredible. I did have halos for the first few weeks but they faded quickly and as I type this its very hot outside so I know I'm going to need additional eye drops, especially in my left eye, and I'm making sure my sunglasses are close to hand but that's it, the procedure, for me at least has been a resounding success and I am very grateful for the opportunity to see without glasses.

So, one last question - Will I need glasses again?

Insufficient information to answer that. There is a chance that as I get older I'll need reading glasses. This is nothing to do with laser eye surgery it's just a fact of life and something to do with the back of the eye changing so it cannot be fixed with a laser.

What about short-sightedness? Could it return?

Yes it could. That's also a fact of life. My eyes should stay at 20/20 for 10-20 years, after that they might deteriorate again, if they do I can get them lasered again for no additional cost which is a very fair deal to me and depending on my age at that point I might not bother but that's something to decide in the future.

LASIK Part one

Two months ago I underwent LASIK eye surgery to correct my short-sightedness. Several people have been asking for more details and what the downsides of it all are so I thought it might be easier to write it all down and point people here.

First of all, I'll provide a little bit of background. I started wearing glasses when I was about 11 or 12 and over the years I became more dependant on them to the point that I couldn't see a thing without them. Before I had LASIK I was -4.75 in my left and -4.5 in my right. My eyes were getting worse at the rate of around -0.25 every four years.

I was one year into a new prescription and on leave when I spotted an offer from Optical Express to go for a free laser eye surgery consult so I decided to go along and see what they had to say.
The consult itself was an interesting experience with my eyes measured every which way I could think of and a few I couldn't.
Part of the process included putting eye drops in that forced my pupils to dilate fully and stay like that for a few hours, going home after that wasn't fun because there was far too much light coming into my eye but that discomfort only lasted a few hours. The tip here is TAKE SUNGLASSES!!

So, with the consult out of the way and with a rather expensive bill for the actual LASIK procedure I had something to think about. The actual cost was nearly 10 times more than the adverts promised but it was because my eyesight was so bad and my pupil size so big. This meant that the only option I had was all laser LASIK with wavefront guided technology, this wasn't an issue as I was already only interested in all laser LASIK. I'll explain the reason in later entry when I explain how the eye is shaped during surgery.

Anyway, after a discussion with my wife about the procedure and the cost it was duly booked 2pm in for the Bluewater shopping centre which is about 15 miles from where we lived. The nice thing about Optical Express is all the follow up work could be done at my local Optical Express, only the surgery had to be done in a specialist centre.

So, the day comes and Krys drives me up to Bluewater, we have lunch.... rather she has lunch as for some reason my appetite has deserted me then the clock rolls round to 13:55 and off I go...

Now at this point I was half expecting them to take me in, shoot me with lasers and I go home but nothing is that simple I end up having to fill out a few more forms and sit there for half and hour.... and it was that 30 minutes which was a total killer, all thoughts going through my head about the bad side of LASIK, the warnings and I'm almost ready to make a run for the door but I manage to hold my cool and I'm duly summoned.... to have my eyes checked, again...
Turns out that one of the scans they took of my right eye wasn't good enough for the surgeon so it was to be repeated.
These scans are vital though as they show how light enters the eye for the wavefront laser to do it's job.

15:00 rolls around and I'm summoned in to speak to the surgeon who asks me if I fully understand the risks and if I'm ready to do this. A voice at the back of my head squeaks 'no' but my voice, probably an octave or two higher says yes and then it's time....

I get lead into the theatre and the room is BRIGHT white, I mean the sort of white you get in a Star Trek episode or something. it's GLEAMING. I get introduced to two people, one is a nurse the other an assistant laser specialist. I get to put on a funky hair net and they lay me down on one of the most comfy chairs ever.

Then the laser surgeon arrives, my heart rate goes up a notch and at this point, it's all down to business. Some eye drops go in to numb the eye, an eye patch goes over my left eye, something metal goes over my right eye, there is an INTENSE pressure on my right eye and I'm seeing all sorts of funky colours which I guess is down the pressure of this metal contraption pressing down hard and causing nerves or light cones to fire off randomly. It doesn't hurt, it's just a little odd an uncomfortable, they roll me to my right and tell me to hold very still and look at a white light, the light flickers and that's the flap in the cornea created. I think it was the assistant surgeon that then moved something over my eye which pulls back the flap and my eyesight goes straight to shit, everything is splodges of colour and at this point I'm grateful to whoever it was who said "you won't see much, don't panic it's normal" because my left eye is covered and my right eye is a blur.

Then I had the most disorientating thing I have ever experienced, bear in mind that my left eye is covered, my right eye has no cornea covering the pupil so I've no vision in my right, just blurs and then the damn world MOVED. Turns out the chair I'm laying on rotates between laser devices but I didn't know this, all I sense is the world moving and I've got no visual reference for it so I'm gripping the chair in a death like manner until I realise that this is normal and I'm not falling...

So, I'm now pointed at another laser machine and the assistant surgeon tells me to relax and look at the orange flashing point to which I respond "which one?!" as thanks to my now very blotchy vision I can see about 9, the assistant surgeon tells me that it doesn't matter and once again to relax so I try very hard to but it's a little difficult. The surgeon tells me that I need to hold very still and that there will be a smell of burning which is normal as it's just a byproduct of the machine, others have told me that it's the smell of the surface of the eye being ablated but I prefer the byproduct thought. Anyway, the surgeon puts his hand on my head quite firmly.
I'm once again told to relax then there is a loud clicking and the orange light pulses, in the background I hear the nurse count down from 30.
Now, what's amazing is as she goes '3...2....1' my vision clears, from 9 dancing orange spots to one very well defined one - already my vision is far better...
They move the chair again, something passes over my eye and then some eye drops are squirted in. My right eye is done.

The process is repeated for my left eye and I won't go through the details for it suffice to say that's it's almost the same. When they created the flap apparently I squinted a little and put too much pressure on my left eye which caused some temporary damage and swelling but I'll go into a little bit of detail about that later.

The whole process for both eyes took no more than five minutes, was uncomfortable, not painful and was performed by some really friendly people. Once the procedure was done I was lead into a darkened recovery room and told just to relax. In the room were a few paintings which I could SEE without glasses... amazing.

One of the nurses gives me a little goody bag of eye drops and I'm told very firmly "DO NOT rub your eyes". My eyes feel very gritty and there is a film over them which is all quite normal.

So, I give my wife a call, she comes in to collect me and drives me home, at this point I realise that Optical Express is right across from a store that sells... lamps, which are on, causing all sorts of halos and weird optical effects right in front of me. Who the hell thought it was a good idea to put a lamp story across the concourse from a Laser Surgery facility?!

The drive home was interesting as I couldn't look out the windscreen because it was just all too bright, the few glances I did steal were awesome because I could read car number plates without glasses!

That's probably enough rambling about the procedure, I'll cover the aftercare and some other things in later posts.
In summary it was one of the most uncomfortable and disorientating experiences of my life but it was very quite, certainly painless with results that I could literally see seconds after surgery.

Exploring the Job Market

So it's that time of year again, appraisals - the part where you sit down with your manager, he tells you just how useful you are and how you don't quite get a bonus because you never exceeded the goals set despite the fact that exceeding the goals set would require changing the laws of physics. Part of this cycle of horror is "career development" which always makes me laugh as, so far, I've never been allowed to 'stretch myself' to the areas that I want to try my hand at yet every 6 months we go through the same dance...

Anyway, with the advent of the Appraisal coming I decided to start looking at the job market again an found that most of the ads were the same:

"Seeking person to look after servers, storage, VMware, service desk, support calls, other people, animals, wash boss types car, work under pressure to tight deadlines. URGENT!!"

And there it is. Three phrases I hate:

"Work under pressure" - basically means the boss will tell you that something needs doing five minutes after it should have been done. On a Friday. at 16:55.

"tight deadlines" - This is a negotiation that happens up and down the country. Boss type says project x will require six months. His boss says "great but you have 3 months" which then gets passed down to the team with some hokey speech about teamwork, pulling together and camaraderie.

"URGENT!!" - I hate this word more than any other in the English language. In nearly 16 years of IT work I've come across a handful of truly urgent situations. Most of the rest are because someone didn't plan, panicked and needs to cover it. Any job ad that shoves "urgent" in there is (in my mind anyway) incapable of planning for even the short term.

Depressingly most places seem to use the above three phrases interchanably. It seems that IT jobs are not real IT jobs unless those three phrases are used.

I think that maybe I'm getting just a little bit jaded with the IT sector these days as for something that's considered an Engineering discipline it doesn't seem to be maturing in the same way that the engineering sector has.

New Phishing scams in progress?

I think we've all had those emails from the Banks "security" department and which threaten all sorts of mayhem and chaos if you don't go to the site right now and type in all your security details which then gets sent to some dodgy bloke in an internet cafe in deepest scam land, well, yesterday I saw a new twist on it in the form of two emails.

The first was from an IT recruitment agency and it was the normal "we are wonderful, we are awesome, send us your CV" and I didn't think much of it until I saw the email address under the link - it was a yahoo mailbox with what looked like one of those auto generated addresses.

The second came from "undisclosed" and was talking about a webmail upgrade. My hosting provider recently upgraded their webmail portal so at first I thought this was part of that work until I saw that it had been through a mail server in the ukraine then when I read the email more closely I saw that they were asking me to reply to them giving my email address and logon password. Now, my hosting providers security is atrocious as they use the account password for verification purposes (which must mean that staff can see it) so I can easily see people getting duped into sending this information. Of course, the reply to address wasn't a legitimate address and so was another phishing attempt.

I'm now wondering what other scams are out there... I'm also thinking of changing hosting providers due to their terrible security policy.

Common questions - Why doesn't NTP set the time?

Because that's not how NTP works.

NTP will take the machines current time and compare it against a reference server (or servers) and then work out how much of an offset to apply.
If your machines clock is only half a second or so out then NTP may well make just one change to bring the machines clock into line with the reference server but if it's more than than then it will apply clock slewing to gradually bring the machines clock into line with the reference server.
In testing I've seen NTP on a a machine with 8 seconds lack from the reference time server take 15 minutes to slew to NTP time.

Why doesn't NTP just set the correct time in one go?

Because of our old favourite - security.

Lets imagine a scenario - User A logs on to the network at 09:00:00 (according to NTP time). His workstation is 10 seconds fast so according to his machine the logon is at 09:00:10 - this doesn't cause any issues for authentication as it's well within the allowed time range.

User B is an evil user. He has just captured all of User A's logon traffic.

NTP now corrects User a's machine clock to be 09:00:01 which is the same as the time on the NTP server.

User B replays User A's logon request. This request includes a timestamp. The authentication server (lets say a Windows Domain controller) accepts the request and compares timestamps, this new request from User B will APPEAR to be later than the original from User A and so the domain controller grants access.

The above is a very, very, very simplified view of domain logons, in the real world it wouldn't actually work due to how times are recorded and how password authentication actually works but it provides a simplistic view of why time skew is in place of a forced change.

Offsite Vendor presentation meeting

So I've been meeting most of my targets and have been fairly organised work wise and this has now come back and bitten me because I've been told that I need to go to a vendor presentation meeting tomorrow miles from the main office and that it starts at 09:00 SHARP! (There was emphasis on the sharp bit, it's not me doing it for effect).

So, it's a very early start, trapse across country to hear a salesweasel enthuse about something I really don't care about and don't even have much knowledge with. The only think I can do for my own amusement is think up awkward questions and see if he (because it's always a him, no sexy nible women to push the sale unfortunately) and enjoy the 'free' lunch.

In other news, very soon I should have 168TB of shiny SATA disk to play with. This is far in excess of what we really need but it'll help collapse 20 disk shelves of 72GB disks into just 3 disk shelves of 1TB SATA. I really, really love SATA disks and think of the improvement in sizes, 72GB which were state of the art 6 years ago to 1TB today. It's quite incredible.

The drawback here is that of spindles, more data on less spindles means that different people could cause the filer to fight over access to the data. This can be fairly easily mitigated by dividing the aggregates (the physical disks) in sections that will have specific usage patterns.
In many ways I'm looking forward to this project as it will really help consolidate a lot of the NetApp filer works I've been doing and provide a lot of room for growth.

Catching up

I've been a bit remiss in not updating my blog for several months. A few combinations of a sudden urgent project, the wife having knee surgery and a flood at home all conspired to steal a lot of my time and then, of course, the inevitable run up to Christmas with all the fun and games of Christmas shopping in the snow.

I have been thinking about what to do with the blog, should I continue it? should I change it or should I just close it? I'm not playing with enough new technology to bring anything wonderful and astounding to the site and my time is ever more limited but I'd like to keep the blog going with a few war stories and other things.

Thoughts?