Now I will help you maintain your eyesight because it's very important!

Firstly:

Clean your monitor. Yes, perhaps dust in the corner has formed a beautiful pattern, but it might turn you into a glasses wearer if you stare at it for weeks.

Secondly:

Avoid sitting in the dark as it strains your eyes twice as hard.

Thirdly:

The monitor should NOT be placed in front of a window. It's obvious, but let me explain: Light falls onto the monitor and darkens it.

Fourthly:

Take breaks. After each gaming session, stand up, blink, stretch, and look out the window. Maybe there's dirt and humidity outside your window. Then gaze at the sky. At the same time, you'll take a breath and gather strength for the next game :)

And yes, if you're sitting for more than 5 hours, take a one-hour break (not on YouTube, just rest).

Fifthly:

Sit properly. Of course, it's cool to sit on a stool right next to the monitor, but it's better to have something more comfortable with back support. Otherwise, you'll end up hunching over and squinting like an old grandfather.

Also, maintain a distance of an arm's length from the monitor!