the review I cited rang a bell....

by former hater of plastic, Friday, June 29, 2018, 09:47 (2341 days ago) @ former hater of plastic

As being a glasses wearer, such things become expensively plain when buying sights/optics.

If your natural eyesight, or assisted with glasses eyesight, will not allow you to focus on something, or focus only with unnatural head position, on anything that distance from your eye, whether cheeked or held at arm's length, then the sight will be out of focus. It will be impossible for the SAOS acrylic lens to focus sharply at both distances, for sure.

I have found that, today, if it does not have a diopter, it is pretty much useless, or no better than open irons. This about useless catagory includes tube sights and ACOGs.

If the bifocal (low or high) or sweet spot of progressive lenses with natural head position, not set exactly for distance to focal plane of the sight (including the SAOS lens), then it is going to be blurry, no matter what a reviewer says.

These comments for anyone hoping the SAOS, or any other miracle sight, will allow getting back the great vision of youth. It can, if glasses dialed in exactly for that sight on that gun at that distance, otherwise, all Lady Luck.