They both should require an optometrist check to make sure the glasses match your eyesight.
But, the healthcare system being what is, both in terms of cost and availability, it is a better option in the long run to make the most commonly useful prescriptions cheaply available than not at all.
I’ve only ever seen correction glasses offered off-shelves in North America. In Europe and Japan you are ~~required~~ strongly advised/supposed to go see an optometrist or ophthalmologist (in some places, the distinction does not exist).
Latest Answers