I just completed Open Water Diver SCUBA certification in Belize with my new prescription mask. It works amazingly! The mask is very comfortable, the view excellent. The quick-release headstrap has come in handy more than once, saving my hair from potential damage. Although I've found I don't much use the reader stick-on lens to see my SPG readout (I got one on the right lens), I'm still glad it's there, as rented gear with a dive computer may look different in the future. I opted for a mask prescription of -4.5, with which everything is in sharp focus without appearing overly close (my progressive glasses are -5.25, my computer bifocals are -4.25). The high-quality tempered glass offers a large, clear viewing area. I haven't had problems with fogging. The shape of the mask maximizes my view without being obtrusive; it fits nicely over my face. I'm so happy I bought this just before getting SCUBA certified! I saw SO much marine life, in clear focus, over three days of diving. The mask is great for snorkeling, too!