If you use your screen (phone, PC, tablet) at an unnecessary brightness, you could get used to it being dimmer and dimmer — Dim it until you're only just comfortable, get used to it, and repeat.

Use the blue light filtering Twilight app, or similar, all day, and intensely in the evening. During the daytime, you can have it set to ~1240k colour temperature and 60% intensity. At night, you can have it set to the lowest colour temperature and 100% intensity. You can set up an accessibility button, to easily toggle the Twilight app’s overlay on and off.

On PC, generally or always use “Night light” and/or the f.lux app or similar to manage blue light. Needless blue light exposure will damage your eyes, particularly if your monitor is bright. You can get a BenQ eye care monitor or similar if you want your screen as dim as possible, though I haven't researched this. Matte is better than glossy obviously, for general viewing comfort and function.

If you often lean forward or point your neck downwards a lot, you risk a misshapen neck and spine, with your neck visibly coming forwards instead of holding your head directly above your shoulders.       How Your Phone Is Changing Your Posture  ← he didn't mention you can just hold your phone higher

Neck bent forward – "gamer/nerd neck"

The posture required to produce such a neck is not healthy, let alone the spine shape itself.

However, being in different postures while sitting is more important than not being in the "wrong" posture.

When sitting in your chair, avoid slouching forward or slouching backward for long periods of time or as your usual position. Generally, let the back of your chair support your back the way it should. The center of your monitor should be around eye level. It’s better if the middle of your monitor is slightly higher than eye level than slightly lower.

In general desktop use, your keyboard and mouse should be far forward enough that your forearms are completely supported, rested on the desk. Your elbow(s) may be just off the edge of, or just on, your desk.

You want to be forward enough that your arms are supported, and backward enough that you have a healthy posture and not a consistently forward-leaning posture.

You should use a monitor arm to hold your monitor at eye level and also it takes less space on your desk e.g. https://www.amazon.co.uk/dp/B0765Y4CT5

If you don’t have a good office chair with a movable back, you may do well to put a lumbar support pillow on it e.g. https://amzn.eu/d/7dnq8kD

I recommend Ergohuman chairs or similar, though I don't have one.

If your chair has wheels and you don’t want it to move easily, you can replace the wheels with bell glides.

If you use headphones, open-back ones are best, minimising pressure on your ears (e.g. Audio-Technica ATH-AD700X). These headphones are great for spatial positioning and have a wide soundstage.

¼ teenagers have hearing loss.

The closer a source of sound is to your ears, the more easily it can damage your hearing.

You can get a hearing test to find out how relatively deaf you might be.