Tri-focals do not work for me progressive or not. I use two pairs of glasses. Otherwise the lenses are way too thick.
Here is a swell trick-learned from the board members here. Press the keys-ctrl & alt & move that mouse wheel until the letters and size of print is readable. Oh wow, what a difference. Just love that. So I do not need that third pair those magnifiers. I can read the computer screen with either pair. Happy quilting everybody.