What I like about this theory is we can test whether or not it’s true for ourselves by simply wearing slightly weaker glasses and seeing if our vision improves. The cost is relatively low and it would be fun to do.

Interestingly enough, it does seem like eyeballs can shorten in many species, including chicks, shrews, and some primates. It only took a few seconds to Google.[1]

I’d be curious whether humans share a similar mechanism. I would be surprised if they didn’t, considering how this mechanism is common amongst such a diverse range of species.

Cheers.

[1] https://iovs.arvojournals.org/article.aspx?articleid=2189093