On Sat, 15 Mar 2008 21:20:10 -0700 (PDT),
wrote:

warn pilots to NOT use progressives for
flying due to distortion affects.

Human eyesight is truly astonishing in its ability to adjust. Whatever
change you make, you will need an adjustment period. (My father was a
carpenter. He got bifocals at age 48. The first day he wore them, he
was on a scaffolding. He glanced down, took a step, and stepped
between the planks. Gave himself a hernia recovering.) Once you
adjust, you will scratch your head wondering what the problem was!

Years ago, test subjects were given prism glasses that turned the
world upside down. Within a few hours or days, their eyes switched
over and they saw the world rightside-up. And of course when they took
the prism glasses off ... the world was upside down again!

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
new from HarperCollins www.FlyingTigersBook.com