"Possibly your goggles get loosed when swimming . Make sure you are wearing your goggles properly. The strap should go over the crown of your head. Make sure that the nose piece is adjusted to the right size.Then try to dislodge the goggle eye cups by making faces in a mirror. If both eye cups remain firmly sealed around your eye sockets, despite your best attempts to loosen them, they're not likely to leak as long as you take good care of them.Keep your swim goggles dry and out of direct sunlight when not in use.
source : http://www.livestrong.com/article/80085-stop-water-getting-swimming-goggles/#ixzz1rhJds2O0"