Why do some people have worse eyes?

I have been wearing glasses since primary school, it started with -0.25 (left eye) and -0.75 (right eye). I'm now 20 and my values are -1.25 (left eye) and -3.00 (right eye). Most likely, the values have increased again, because I have to do everything on the laptop due to the current situation.

My brother (15), in turn, is playing all day, he gambles from morning to evening and his eyes are great! He never opens the shutters in his room and squats in the dark with his PS4 and his cell phone.

Why is it so? Why do my values deteriorate continuously? I make sure that I don't use my cell phone too often and that my room is always bright. Unfortunately, I have to say that since I started studying, my eyes have gotten worse.

Defective vision has something to do with an eyeball that is too long or too short. So it comes from growth and has nothing to do with "too much gaming or too much screen or too little light".

For me it is unfortunately the same, only that nothing has really changed for me, neither positive nor negative. The first values that you specified first have been roughly the same for 20 years now. Can change with every new pair of glasses, but this does not have to. I had squinted when I got my first glasses, which was later fixed. Today I only have problems reading the small font size 5 on my PC / laptop with great effort, only if a long text can be read. Depending on the font, I can read better or worse from there. I think it's great that there are so many free fonts and you can find your own legible and beautiful-looking font. Without glasses I get a headache and see everything a bit blurry, very small letters e.g. At the train station, etc… It's just a good thing that my poor eyesight is not impaired too much. Without glasses, the eyesight naturally deteriorates, so wear it where you would not want to wear it, even at home. I always wear them except when I sleep because I get headaches quickly and it strains my eyes. Why the eyes worsen or even improve with the respective people, can't be said exactly why it is so with some and not with others because he gambles a lot. I guess who gambles a lot and sits in the dark will have problems at some point, being awake and darkness are never good, since the circulation adjusts to having to be tired and then logically there's also time to go to sleep and then continue to gamble if your eyes hurt later, you become irritated, forget about time, even fall asleep while playing and don't remember what you played where and how. That's how it was for me when I was young, when I had no other needs from morning to evening, taking something with me on my PC, then taking the Amiga Commodore 500 with me to eat, that was additional stress. Play less, enjoy more fresh air outside and treat your eyes to rest. All the sensations, effects, etc… Are just stress for the eye. Then when you get tired, let your eyes shut. That's how I do it. It is also extremely bad how many people do it, hanging in front of the telly or on a PC / laptop. Actually, we do pretty much everything wrong when we hang on the PC / laptop.

For the same reason why one person is 170 cm long and the other person is 200 cm long. The respective genes are responsible for both. The eyes and the body grow accordingly. One needs
Shoe size 41 the other 47, the same reason.