Most people who need an optical correction - aside from the fact that most people need readers by the time they are 40 - are short sighted Most people who are short sighted are female.

There's no selective advantage to being short sighted. When there's no selective advantage to something and yet it 'runs in families' it's not genetic it's cultural.

The eyes develop and they grow and they are shaped as they grow and they develop a shape to suit the task they are given.

Essentially, girl get short sighted because they never see outside four walls.

If you bring up yer boys to play out and yer girls the stay indoors then the girls' eyes will be adapted to see from their nose end to the telly and the boys' will be adapted to spot a football across a field and the girls will be short sighted and the boys won't.