Quote Originally Posted by drk View Post
Still makes no sense to me.

If we're talking about PALs, we're talking about binocularity through skinny-winny corridors. Maybe skinny near zones.

I don't know who but Andy can run with me on this, but hear me out: If there is prism, one eye will, in the binocular state, deviate outwards (let's just use the monocular exo case). So the first-order thinking is "well, the eye is pointing out, now, so it can't use the corridor...".

But here's my obstacle: Sure, the eye is turned out because the prism moved the image out there, but it also moved the corridor out there as well, optically.

The way to test it would be this: take a frame off the board and use scotch tape to make a sliver of clear lens simulating a corridor. Then look through 15^ BI at a near object. (Your eyes will not be converged anymore, but dead straight like you're looking at distance.) Can you see through the openings in either eye (have to judge this in a binocular condition, not close one eye then another)? Or do you see clear in one eye and fuzz in the other?

I"m gonna do it.

But here's what I don't get, and never did (and it goes with the whole short corridor for myopia argument):
It's not to do with measuring. It's to do with glazing. When blocking the lenses, the prism causes the perceived placement of the uncut lens to shift, and so you must compensate for that.