Tinted swimming goggles

I got the darkest tinted goggles I could find for Charlotte.  (These ones from Amazon)

She has been wearing them fine at indoor pools but they did not cut the mustard yesterday at an outdoor pool on a sunny day.  She isn't swimming independently yet so they weren't a problem in the pool but when she got out, she was really cautious about where she was walking.  It was obvious that she couldn't see well at all. The contrast with her behaviour once she put on her tinted glasses was remarkable.  Clearly, the glasses make a huge difference.

I'm not sure how we are going to be able to help her with swimming as she gets older.  Contact lenses under goggles seems like they would easily get lost.  She can wear her glasses for casual swimming but not in the ocean, or proper kid swimming where they are jumping in  and going under the water all the time.  Living in the UK, I guess this is not going to be much of a problem on too many days of the year ;)