How do you know what strength to get OTC glasses? They would probably work quite well for me in the kitchen, where all I need is something to help me read the itty-bitty cooking instructions or do the crossword puzzle from the book that lives on the kitchen table.

For reading an hour or more, I'd prefer to use the prescription glasses, since I have astigmatism and after 30 minutes or so the OTC glasses make my eyes tear up and eventually I get an eyestrain headache.

So your recommendation of store bought glasses would be great (and save money) if I knew what strength to buy.