"BT" wrote in message
...
I've read the posts on Progressive lenses and Bi / Tri focal lenses. And I
have both.
I need glasses for distant vision correction and have since my early teen
years. For years I flew in the USAF with prescribed contact lenses, or
regular single prescription lenses to correct for distant vision and the
younger eyes can adjust just fine for up close work.
But we age, and now I have to correct for near vision.

The eyes are too old to make that forced correction on their own and can
no longer adjust from the distant to near with my "distant" corrective
lenses.. For most of my work, I wear the contacts and keep reading glasses
handy for computer and reading. Now the time has come that I cannot read a
VFR chart or a standard sized approach chart without reading glass
assistance if I have my contacts on.

I know many pilots that have fine distant vision, but use the half high
reading glasses in the cockpit.

I have used bifocals and find them workable, I am able to read the glass
cockpit panels with no problems at the intermediate range.
I have progressives, I have found from driving a car with the progressive
lenses that the periphery vision is blurred.. not as clear as looking out
the sides of my bifocal lenses. This gives me concern that if flying with
my progressive lenses that distant objects (aircraft) in the periphery
will not be clear and in focus and could easily be missed. I find that I
have to look directly at what I want to see and then adjust my view
vertically with the progressive to find the clearest picture. Not what I
want to be dealing with while flying.

A fellow pilot prefers the bi focal, with the line, he knows which part of
the lenses he is using to see out the window, and to see his instrument
panel. His glasses are adjusted, so that at normal sitting position, the
line of his bifocal is right at the line of the glare shield.
**************************************************
I was using trifocals, both regular and blended. Once I got used to it, the
blended was, at least for me much superior.
Then I got a slight case of cataracts, and elected to have the Crystalens
implanted. This basaicaly replaces the original, no longer flexible natural
lens with an accomodating lens that focuses both near and far - the lens
actualy moves back and forth in your eye.
After about 3 months of training I don't need glasses at all. I am very
happy with the results.

Frank