I just ordered some glasses from Hong Kong using my Tesco (free) prescription. Got them - tried them on and the right eye is perfect for reading (which I wanted) and the left eye is perfect for distance (which I didn't want as they are for close work).
Guess who read the prescription wrong and now has to order another pair!
Good job I went for the cheapest ones to try them out first.
Oh well another £12.99 down the drain.