Dave, the suggestion of glasses it's not meant as a sub for prescription glasses. These are effectively just a pair of magnifying lenses in a frame - it's no different in principle from using a magnifier on a stalk, just a darned sight more convenient.
But yes most people 'our' age should get an eye test regardless.
SORRY but you are SO SO WRONG in what you are saying,these are proper glasses not magnifing ones,a Magnifier that you buy varies in focal length for differnt people,what I mean here is that the distance of foccusing for you is differnt to eg Martin.
Now the glasses that are for sale in supermarkets etc etc as someone has allready pointed out have no diopters in them,some people need prisms,each eye is different from person to person.Each eye can differ immensly,some have long vision others have short sight.Some people have a clear lens one side and prescription on the other.
How can you tell if you have a cataract,glucoma etc etc etc
So with this in mind how can you SAFELY say by going to a supermarket and choosing a pair of glasses they are RIGHT for you.........WELL YOU CAN NOT.
If it was as simple as that well every Optician in the country would have to close..............................
End of sermon and biology lesson
Dave