That was the leading theory for many years that explained why adult humans today have much worse vision that humans of the not-so-distant past, but it was dispr

That was the leading theory for many years that explained why adult humans today have much worse vision that humans of the not-so-distant past, but it was disproven in the last decade. We don't yet understand why, but lack of exposure to sunlight is what causes still-developing eyes to grow incorrectly.