> She did notice, however, that the European kids would experience red eyes, irritated by the salt in the water, whereas the Moken children appeared to have no such problem.
That's just an observation and is there is nothing in the article to indicate it's not covered under "other than their time spent underwater using their eyes" is there?
The title of the research paper is "Visual training improves underwater vision in children".
That's a pretty bizarre basis for differentiation - I grew up swimming in the ocean, eyes wide open. never once did I get red eyes. Chlorine in pools is a different story.
It's not just salt, it's other pollutants. The difference between swimming in clear Croatian beaches and the average German (or Italian) waterbody is noticeable.
