https://www.hometownstation.com/news-articles/dial-vision-glasses-reviews-worth-it-or-scam-351738
Why Are Progressives Exactly The Exact Same As Trifocals?

No. Bifocal and trifocal lenses include two or three distinct magnification degrees, separated by an observable line. Progressives lack those tell-tale transition lines. The truth is that lots of people prefer progressives because they do off with the conservative lines entirely on bi- and trifocals.

But the smooth transition is important for another purpose: The sleek transition involving close up and far away viewing averts the"image jump" that people encounter with bifocals or trifocals. This can be really where items suddenly vary in mind and apparent position since the own eyes go across the meds from the lens.