This is a suspiciously good mask, especially for the price. It was leak proof over 4 dives down to at most 18 metres and they never fogged up once! I didn't bother smearing toothpaste on it or anything, though I did use some baby shampoo to prevent fogging, but still pretty amazing. Everything was super clear due to the prescription lenses and it even fit my big nose! I can't say how long the mask will last as the strap doesn't seem like the best quality, but honestly I wasn't expecting the mask to last even this far! If you're considering a prescription mask, skip the expensive brands and just buy this one!