Peter wrote:
I have met loads of people who had glasses made with the rotation (astigmatism correction) made incorrectly
How would one know?
I have been on the receiving end of glasses that I felt quite sure were not correct but I would never be able to say exactly why, other than, I can’t see properly! I have always found opticians rather less forthcoming about their discipline than my family doctor or dentist who, by contrast, treat me as a peer and are more than willing to indulge my curiosity.
How would one know?
By testing one eye at a time, and rotating the glasses to see if the best image is really obtained when the glasses are the right way up.
A good test image is one with some vertical and some horizontal thin lines (e.g. a distant TV aerial at 100-200m) because assuming the basic correction of the lens is about right uncorrected astigmatism tends to manifest itself as very slight double vision e.g. you see two of the aerials, a few inches apart. Most people never notice this; they just don’t see as sharply as they should.
It is usually obvious.
Another test, also with one eye at a time, but more tricky to do, is to poke a finger into various corners of the eye, to slightly distort the eyeball, while looking through the glasses 
If a particular distortion improves the vision, that lens is made wrong. Don’t try this at home, as they say, especially with 15W50 on your hands 
In the UK there is a well known cut-price chain which has messed up prescriptions to a number of people I know, including myself. But to be fair nearly all retailers are capable of it. There is a really cheap mail order place I use which does really cheap glasses and I use them for glasses which I leave kicking around the workbenches at work, and they have to re-make maybe 1/3 of them because they are so obviously wrong!
Removing scratches from glasses
Potentially aviation related
I did a perfect job with Autosmart Restore R1 car polish, in about an hour. By hand, with a rag.
It also removed the anti scratch coating which was the main bit that got scratched!
Update: Renovo Window Polish (widely sold in aviation) works even better.
Does anybody know of a firm or a lab which can do a cheap and dirty antireflective coating, on the above glasses?
They got scratched (mysteriously, since they just lived in the plane) and I sorted them out with the pricey aircraft window polish. They are great now, but the antireflection coating (such as it was – a bit of a con for the money) is gone, and so is most of the tint.
I would not mind if the stuff was deposited all over the whole thing… the glasses now have the frame epoxied to the lenses anyway so can’t be dismantled
My medical now says “Wear”. It used to say"Carry".
My newest gadget – varifocal glasses
(sorry, no picture yet)
This day terminates once and forever my youth. From now on I am old. I just came back from the optician with my first varifocal glasses…
Next week my medical is due and already last year the doctor told me that my glasses are not really good enough for class 1. Especially because I had to take them off to see close-up stuff. Which according to the AME is not allowed in the cockpit, as it is not allowed to have two different glasses (one for the distance, one for close-up). So I went to an eye doctor to have my eyesight checked and got myself a prescription for varifocals. Very strange – I definitely see better now than before (for the first time in years I could actually read the little numbers on the odometer of the car while driving home) but it has become so direction dependent. I hope that I master these glasses before my medical next week – and that I don’t fall down some steps in the meantime and break my neck.
BTW: I think these glasses are the most expensive item I ever bought for flying. I can’t remember the exact figures from back then, but I think that I paid less for my multi-engine rating in 1991 than for these glasses – a single lens is 550 Euros. In my next life I want to be a Zeiss shareholder.
IF you are able to fly a plane fine with your old glasses then one approach to the “medical issue” is to get cheap bifocal glasses made just for the medical You want cheap ones because AFAIK under EASA you need a prescription less than 12 months old and you have to turn up with glasses made to that prescription, so you may need new ones every year… you can get bifocals made on the internet for about €50.
Some people like varifocals, some find them hard. I use bifocals. Some people even get the dominant eye made for distance, the other eye made for the instrument panel, and the reading inserts made for the kneeboard. It takes about 1 minute to get used to it but the result is excellent, if totally illegal.
Peter wrote:
You want cheap ones because AFAIK under EASA you need a prescription less than 12 months old and you have to turn up with glasses made to that prescription, so you may need new ones every year… you can get bifocals made on the internet for about €50.
Hmmm. If so my AME doesn’t enforce that rule.
Like you, I use bifocals when flying. They work great!
