Good for most prescriptions up to 6.00. Due to the open edge at the bottom, standard lenses in 1.5 material are unsuitable as they are easily chipped. And that's not good.

So we recommend, nay insist, that you have at least 1.6 or 1.67 index lenses. (If you're unsure what this all means, don't worry - fill in your prescription details and we'll email you or give you a call).