I’d be curious to know if anyone has been futzing with ‘active’ progressive lenses and, if so, how close to viability they are.
You can make a lens adjustable by using tricks like encapsulating an optically acceptable fluid between the front and rear layers of the lens and adjusting the pressure to adjust the shape(there was a cool proposal to use this to make eyeglasses available in poor regions without optometrists by having liquid-filled lenses that could be user-tuned while being worn).
You can also get fairly compact laser or ultrasonic rangefinders(potentially both to cover overlaps in which one works best at various distances); so, at least in principle, it seems like you could have a set of glasses that adjusts itself to the distance of the object being corrected for across the entire lens.
This would obviously sacrifice passivity; and I’d imagine that it’d be nausea hell if the ranging and adjustment process wasn’t really, really, finely tuned; but it would avoid some of the cruder heuristics of just grinding different parts of the lens differently and assuming that the user will do different things at different angles.
