Isn't it rational to think that staring at screens close to your face for extended periods of time, aka using the muscles around your eyes for an extended period of time, will elongate the shape of the eyeball? Isn't it rational to think that this elongated shape isn't optimal for sight? Isn't it rational to think that how you use your eyes will affect how you will see in the future? (For example, older people often don't suffer from myopia but are instead far sighted because they spend more time looking at things in the distance).

Why does everyone keep telling me that this is irrational and the only thing that affects eyesight is genetics?