It's costly when you have to regularly change your prescription lenses, particularly with heavy computer use leading to astigmatism. So the idea of adaptive lenses whose strength can be adjusted with a twist of the dial on the side is certainly a novel and inspired one.
Adlens' adaptive-lens eyeglasses have hollow lenses with a clear plastic sheet stretched across on the inside. Twist the dial, and fluid pumps in between the sheet and lens, creating a high refractive index. More fluid means more curvature, which means more powerful lenses. When the oil is pumped back out, the lens curvature flattens, reducing the power.
Not surprisingly, the clunky Adlens glasses (which come in universal and reading forms) are aimed at the developing world, where function usually overrides form. Hopefully, by the time the idea takes widespread hold for those of us with variable eyesight, Adlens will have taken more of a designer focus and incorporated its idea into eyewear that won't look like something the Nerd Herd would don.