Eyejusters are reading glasses with dials on either side, allowing you to "tune" each lens in real time:
"Two hidden dials change the lens power instantly—just like focusing binoculars," the eponymous company writes. The glasses feature "thin, lightweight adjustable-focus lenses made with our amazing optical technology." Unsurprisingly, they do not elaborate on how they work.
Each side is independently adjustable, and the lens strength range is +0.50 to +4.00 D.
The glasses run about $90, which is far less than I paid for my prescription reading glasses. I'm curious enough about these that I just ordered a pair, and will let you know if they work as advertised.