right goggle always fills up halfway - help!

I've tried multiple goggle types - through to the more snorkel mask style ones and I always have the same problem.

At about 750m (I'm training for the 1500m swim) my right google starts filling up with water. The googles are usually fine until around 20-30 laps into a session.

Then I either have to stop or tread water while I clear and refit the googles. That breaks up my training and afterwards the seal doesn't last very long. The water usually starts seeping into the right hand side a few laps later. This goes on and gets very irritating.

It happens every time I swim and therefore I think it will surely happen in the event unless I find a magical solution. It ruins my time as I have to stop and it also makes the experience much more uncomfortable. I'm happy with my swim technique, strength and fitness and this is the only thing that gets me really nervous.

Does anyone have any tips or prior experience with this kind of problem? I'm wondering whether I frown as the effort increases and maybe that causes a wrinkle that lets the water in.

Thanks in advance for any suggestions!