alt Hacker NewsOptical engineer here. This is what they don't tell you about continuous/transition/progressive bifocals: optically they don't work. The lens design is an overconstrained optimization problem and the solutions they come up with end up compromising a lot on everything, to the point that it is practically useless.
Aren't the bifocals just a convenience over quality? It's inconvenient to wear two sets of glasses, but why would one wear bifocals while driving? This convenience can come at a high price!