I’d like to thank you for your patience and excellent guidance in helping me with my order on the phone. My order arrived (even with the last minute changes) within 3 days. I am THRILLED with my snorkel mask. You calculated my spherical equivalent despite my heavy astigmatism and I can SEE! I had joked with you that I was willing to use the stock prescription lens even if it wasn’t perfect as a cost saver because I wasn’t planning to do neurosurgery under water. Well, the vision is almost good enough! Too bad I’m not a neurosurgeon….