NavList:

Paul,

Nice solution.  I was really happy with this lense correction. For a long time, I thought the optics on my two sextants were just poor quality. I made a second bad assumption thinking the the focus ring on the scope would replace whatever my eyeglasses were doing. Both assumptions were wrong. The optics are quite good, certainly more than enough for doing celestial navigation and the more demanding lunars shots.

As far as focus compensating for astigmatism, well certainly not. Focus assumes perfectly spherical corneas and I don't have that.

Both of us are lucky to have found this fix. Wish I had thought to check the NavList archives sooner, you post would have popped up.

Ed