I am not amazed you can fly with varifocals but I am amazed you can land a plane with them with a tight circuit.
Hmmm, 500 quid? 
Add a couple of hundred.
Oh, we can fly very tight circuits. 
I went for SpecSavers executive bifocals and the split is higher up the lens than a normal bifocal.
Think it was 2 pairs for £89 lol, and their men’s aviator frames, as had much bigger lenses than the women’s ones. Also had the prescription reduced by .25 as the initial prescription made me want to move back from the panel. They remade them for no extra cost too.
executive bifocals and the split is higher up the lens than a normal bifocal.
Exactly right, for flying, and actually a similar thing for driving.
prescription reduced by .25 as the initial prescription made me want to move back from the panel
You are lucky it is only a small change. When you get the 0.50 or more it gets tricky, and then this works great but is illegal to fly with
Has anyone considered UV attenuation of different lenses?
I think all sunglasses sold in the EU are supposed to be a “UV400” spec, but a dropoff at 400nm, while a lot better than plain glass or plain polycarbonate, doesn’t do much for eye protection
There are numeous manufacturers who make claims for better attenuation, even out to 450nm, but I have come across only two who publish graphs: the one above, and Lutina. The most heavily marketed and overpriced sunglasses, Maui Jim, have no actual data… just nonsense like “blocks 94% of UV”.
One can order Lutina lenses via an optician. Justine just paid £290 for single prescription lenses only. The other, Shamir Lens, I haven’t tried but might because they do bifocals whereas Lutina do only single, and progressive (varifocal) which is of course all the rage nowadays because the cheap online traders can’t easily sell them.
I don’t know how much UV comes in via light GA windows but I bet nobody thought about this when the material was chosen. A quick google on plexiglass shows a large variation across materials, but one would think a good UV resistance is necessary otherwise everybody would get a very rapid sunburn at altitude.
Standard polycarbonate is pretty good
but I don’t think aircraft windows use this.
Just recently mad the comparison beteeen Zeiss fun 70% blue attenuator and standard 80% glasses. With the latter, i had difficulties reading the iphone mini2 in bright sunlight un the cockpit. For me, this is safety-relevant, i will therefore only use non-tintet or the 70% zeiss glasses in the future.
Is that this one?
That looks like a normal brown tinted lens.
Bare tablet screens are not that readable in sunlight, anyway. I did a load of testing years ago, ending up with a matt screen protector as being more or less necessary, but you also need a lot of brightness for cockpit use.
That‘s the product. Brown is a dark orange. But the spectral absorption is a little different and 70% is markedly and visibly brighter than the usual non-aviation sunglasses. The zeiss fun look orange for the wearer as well as for the spectator.
I guess the limited brightness of consumer tablets is more proplematic in greenhouse cockpits than in those with a tin roof…and screen brightnis might be one of the last definitive advantages of the apple products.
Some interesting stuff in there, but good luck getting some of it made e.g. the non-uniform tints.
Medical & Glasses
How does the UK CAA glasses requirement work?
If I do wear glasses (minimal correction for astigmatism and short sightness), will I automatically have a “glasses” requirement on my licence, or does the requirement only depend on a “functional” test (e.g. if I’m able to reading some chart with letters successfully without glasses, I don’t get the requirement on my medical)
When does one require a 2nd pair of glasses on board? (I only own one, I can live very well without my glasses)
