Is it possible to purchase myopic far sighted eyeglasses at the drugstore without a prescription?

No: Myopic person is near sighted that means the person can see near but not distance. In order to see distance you need prescription glasses. The store glasses are for reading near they are magnifier or plus lenses. It may work for a far sighted person who can see far better than near. The far sighted person needs magnifier plus lens to see far or near.