PAL focal points

[majucalicut]

Do a progressive lens have focal points?
If yes, how many?

[sharpstick777]

Yes, technically because of the distortion, caused by irregular surface astigmatism the number is infinite. Even down the umbillic, the center of the corridor, the number of usable focal points would in theory also be infinite, just as there is an infinite number of points along a line.

Its what makes progressives both such a challenge and opportunity.