h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

As a RGP wearer I loved your entry. The only thing I don't agree with is the part where you say that the first pair never fits. I have an astigmatism and my prescription is -9.75 in both eyes, yet my lenses fitted first time in both eyes, they did do lots of measurements before hand though and I have regular check ups to make sure they still fit.

Checkups are fun because they because they use a UV reactive dye to see if the lenses are sitting on a bed of tears correctly, I really ought to see if it's available for clubbing, though it only lasts a few minutes and stains everything orange in the mean time!

The Acanthamoeba protoza fails to have been mentioned, I feel it is a fairly important part as it is the reason contact lenses cannot be cleaned in tap water.

Other than that it is a brilliant article

Mel

As a former soft lens wearer and a former gas permeable lens wearer, I can certainly relate to the painful process of inserting the lens. One additional hazard of soft lenses is that they are easily torn by the ragged edge of the fingernail or clipped off by the edge of the lens storage basket. You're not supposed to wear a lens once it has been clipped -- it affects the fit, for one thing, and might scratch the cornea, for another.

Incidentally, my optometrist switched me from soft lenses to gas-permeable in order to slow my rate of advancing nearsightedness. He explained that the "hard" lens helped to shape the eyeball. It seemed to work, but I was so much more aware of the presence of the gas permeable lens on my eye that eventually I gave up wearing contacts altogether.

I used to wear RGPs I now occasionally wear daily disposables. They're so much better. I usually wear them for doing watersports and the odd sunny day.

My lenses stop my prescription getting worse too quickly, that's if I wear them enough, at the moment I don't wear them alot because I am in front of a computer all day, Besides I like my current pair of glasses!

Mel

You seem to have had an expert optometrist Mine said prescribing RGPs /is/ a matter of trial and error, even after using plenty of that fluorescent yellowish fluid. But in my case, the second set was it The glasses are stored in the car now, as a backup means. I've put them back to use only once since then, which was after I broke one lens while really gently rubbing it clean. But I seem to have touched it somewhat too hard with a fingernail, and it went.

This is a great review of contact lenses.
I've found that the best optometrists for contact lenses have worn the lenses themselves. They seem to have a better feel for them.
Back about 25 years ago, one of my optometrists was drilling holes in the middle of hard lenses to get more oxygen to the eye. It worked pretty well, except for the time the lab didn't round the edges off. Ow! Ow! Ow!
I've been wearing lenses for 30 years now. I have become an expert at removing the U-bend from under the sink, as well as finding lenses on any kind of surface. However, since my glasses are the thickness of Coke bottle bottoms, I wouldn't trade my lenses for the world.

This is a great article, but I notice that it warns that if you don't rinse your lenses properly it will be uncomfortable. The instructions with the chemistry talk about 'discomfort' also.

This is true as far as it goes, but it's a bit like saying that the surface of the sun is quite warm. I once put a lens in without rinsing it properly. I will never do it again. If I try to describe what it felt like, I'll have the moderators down in a flash. Suffice to say that it really, really, really hurts. A lot. And then your eye is watering so much and stinging so much that you can't get the offending lens out. Trust me - rinse your lenses!

BTW - how do bifocals work? If the lens stays centered on the eye, or floats up with the lid as RGPs do, then how do you focus precisely through a specific part of the lens at will?

Bifocals are weighted so that they sit the right way up on the eye. Also I only notice the movement of the lens when my eyes are tired other than that I don't see any movement. I ahve an aunt (once removed I think!) who wears one long sighted and one short sighted, I can't remember why!

My lenses were fitted right first time by Boots opticians, maybe I was just lucky but they never suggested that they might not fit, as I said though they did loads of measurements using some groovy machines as well as simple ones like holding a ruler up in front of my eyes!

I've never lost my lens down the sink, I have however mislaid one on the beach (which I found) and my friends kitchen floor (which I found the next morning!), Actually come to think of it I've never actually lost one, I've misplaced them but found them again..... lots

Mel

Your aunt is suffering from presbyopia, and there's a section about wearing contacts of two different powers at allaboutvision: from their front page, goto contacts, then bifocals, then look for 'monovision'. The point is that, if wearing bifocal lenses, it takes time to adapt from near to far. Choosing monovision lets you have both eyes constantly adapted, but one is adapted to near vision and the other to far vision. The price is a lack of 'stereo' impression (depth perception).

ahh now I understand, she said it was strange at first but that she soon got used to it, a bit like only wearing one lens I'd imagine, if you're not careful you find yourself walking in circles!

Mel

Aha, thanks - it all makes sense. I have to wear toric lenses to correct my astigmatism - they are also weighted at the bottom. Because I also have a strong prescription I've not been able to obtain disposables and I find my lenses become less comfortable over time, despite careful attention to cleaning and maintenance - and they're expensive too, so I've gone back to my specs.

Aha, thanks - it all makes sense. I have to wear toric lenses to correct my astigmatism - they are also weighted at the bottom. Because I also have a strong prescription I've not been able to obtain disposables and I find my lenses become less comfortable over time, despite careful attention to cleaning and maintenance - and they're expensive too, so I've gone back to my specs.

How long did you wear them for, over a day that is, because the max suggested wearing time is 8-10 hours, mine do stay in longer sometimes but at the moment I only wear them once or twice a week to keep my tolerence up, they just aren't feasible for all the computer work I do.

Also some peoples eyes just aren't suited to lenses, they either don't produce enought tears, or they are of the wrong consistancy.

Mel

About monovision, what makes me wonder is that it works at all! When I was wearing glasses and one of them went kaputt I had *severe* headaches if I tried to still use them (with one eye corrected and the other not). I had to go through this because it happened while on holiday.

I probably tended to wear my lenses too long when I got my last new pair (novelty!), but I stopped wearing them for work because I also use a computer a lot. I was told by my optician that i had particularly 'oily' tears, which probably explains why I'm not as tolerant of lenses as I'd like to be. I only wear my lenses occasionally these days, for sport and such. Oh well, glasses are a lot better then they used to be.

I don't know whether my tears are oily or not but I do agree with you on the cool glasses thing, I have a lovely tiny pair which is a real shock after wearing contact lenses coz my field of vision s sooooooo small now! But I seem to have got the hang of switching between them now!

Mel