Any question answered...

Thanks mate, just checked, Asda and Tesco are both the same, and indeed they are the cheapest for what I need. I am looking at the specsavers scheme, which is marginally cheaper, about £2 cheaper a month, but I don't know if I want to be tied up with a scheme.... Hummmm...

The specsavers scheme includes free eye care check ups, so if you have problems with your lenses or an infection or something, you can go and get checked out. If you wear contact lenses long term you must take care of your eyes properly, not always going for what looks like the cheapest option. Blindness caused by neglect is not fun.