Comparing the DGX masks to the Seavision ones, the DGX ones are cheaper. However, the Seavision ones offer much more choices of customization on mask choices, mask lens color, and frame and frame inset color. I think mine was around $100- maybe $120. It came very quickly, and I've been very happy with it. My prescription has changed 2 times since then, and I'm about to go in for my third annual visit, and its still working great. I can't say anything about the DGX ones. Does the Seavision mask help with my lack of ability to see creatures in the distance in deep blue sea? Nope, but I wouldn't see those with an ordinary mask either. But I can see for night dives now, and I can see the detail on the tiniest nudibranch!