[cfcef]

You can see underwater, but you don't see as well as they do:

> The kids had to dive underwater and place their heads onto a panel. From there they could see a card displaying either vertical or horizontal lines. Once they had stared at the card, they came back to the surface to report which direction the lines travelled. Each time they dived down, the lines would get thinner, making the task harder. It turned out that the Moken children were able to see twice as well as European children who performed the same experiment at a later date.

[Retric]

I suspect this is mostly just a question of how much time people spend under water. When I used to swim a lot I did not notice my vision being worse underwater. I could easily read an underwater wrist watch for example.

PS: I still have better than 20/20 vision. But, I think your eyes age faster than most people suggest as I can't see as well even at just 35 vs 15.