I used to order different types of contact lens online to try, and the online lens distributor would post that a valid prescription was required AND that prescription would be verified, but they never did, this was 3 years ago. NOW, in the last 2 months, i have tried to get different types of contact lens, but 3 onliine distributors have attempted to verify the prescription.......so something has changed in the US. if i want to try a different lens, i have to visit walmart OD for $40 and get a trial pair of lens, wear for a week, then return and have them checked. if the return visit shows the lens are ok, then a valid prescription can be provided. so, its not a large cost but a real pain in the butt to have to pay $40 for a trial pair of different lens.