I've just paid £748 for 2 pairs of Zeiss varifocal lenses, to be fitted in my pre-existing frames. One pair are photochromic, i.e. adapt the amount of darkening to the ambient light. This might seem like a lot of money (it is!) but I felt that these particular lenses were a good compromise between quality and price. You can pay a lot more for not much more return.
I've been wearing glasses since I was 8 and unfortunately was outside the then limit of -3 dioptre for the Class 1 when I wanted to persue a flying career. I understand that I could now easily qualify, but it's too late...
Varifocals. I have seen opinion that they have no place in any cockpit but in my experience that's UTTER TOSH! I took to mine within seconds of leaving the shop with my first pair 10 years ago and haven't had any trouble since. I can go from map to instruments to outside without any trouble. In my view, they are MUCH better than bifocals as you don't get a sharp cutoff and heaps better than the 'look-over' Doc type. I've flown with people using these and they seem to be more of a liability than a utility.
Of course, you have to move your head about a bit with Varifocals, but in VMC you should be doing this all the time, anyway. Periphoral vision is pretty useless for discerning small objects at a distance, you need to really LOOK for other a/c, using the centre part of the retina. Someone once told me that the area of proper vision is subtended by a 50 pence piece held at arm's length; pretty small.
I must confess I haven't tried flying a helicopter so I'm not sure what part of the lens you might have to look through in the hover. How much can you move your head about when close to the ground to be able to look where you're going?
Incidentally, at my recent eye test, the optometrist remarked upon how excellent my corrected vision was, easily able to read the bottom line on the chart with either eye. 'You people who are short sighted are so picky about getting just the right correction!'
I get the impression there are loads of people out there, both flying & driving, who, because they can just get away without having to wear specs, have much poorer visual acuity than those of us who are forced to.
Cheers,
The Odd One