After the wrong prescription review, I went back to the office to meet Dr. Hui. He cleared up the situation by telling me that Sams Club just has a different kind of way of prescribing contact lens. I wish he said that before telling me to take it to Costco for not gaving a membership for Sams Club. The Sams managers was kind enough to allow me do an one time purchase of contacts without membership. However, I think the Summerlin Costco has better equipment and a more common form of prescription making things easier.