Recently I gave the prescription FO2 goggles a thorough test. This included daily swims in the 50 metre pools at Club la Santa, Lanzarote and also in the salt water lagoon which is next to the complex. In fact on Saturday 6th October I competed in the Lanzarote 70.3 Ironman race where I used the goggles, with no problems The FO2 goggles performed impeccably as they alway do. As soon as I put them on they sealed immediately around the eyes and I never had a leakage problem. This included using them for the race where I was in the middle of approximately 400 men starting the swim together which was a bit frantic!!! Because of the choice of different size nose bridges they should fit most size nose/faces etc, I personally always use the largest one. The optical variation of +2.5 left eye and +2.0 right made a huge difference, especially in the race where it made spotting the bouys much easier and also reading small items like your watch etc., and also if you use the pool clock. I would certainly recommend these optical swim goggles and look forward to the release of the blue versions