American optometrists have a racket enforced by law that says correctional lenses can't be sold without a prescription, and patients must update their prescription every year (or two for glasses).
But most people don't really need to update their prescription that often, and buying a new pair of glasses ever other year is expensive and a hassle.
So here's hoping these smart glasses created by engineers at the University of Utah make it past the testing stage- because they automatically adjust to any prescription.
These futuristic glasses have liquid lenses adjustable to any prescription via smartphone app, and the adaptive liquid lenses "can automatically switch between two prescriptions using piezoelectric actuation based on what the wearer is looking at."
-Via Laughing Squid
I see that it's entirely legal in most states for an optician to DUPLICATE a pair of prescription glasses without a current prescription, so you can keep getting new ones indefinitely, without any further exam.