Turn off your dark mode bruh.

I use home-made chrome extension consisting of two files:

{
    "manifest_version": 2,
    "name": "~",
    "version": "1.0",
    "description": "Disables background on codeforces.com",
    "permissions": ["https://codeforces.net/"],
    "content_scripts": [
        {
            "matches": ["https://codeforces.net/**"],
            "css": ["style.css"]
        }
    ]
}

body {
    background: url() !important;
}

well is there any way to keep the snow theme? its sooo goood ;)

Go to more options in dark reader and select filter+ instead of dynamic and also enable only for current site options.

does dark mode puts less strain on the eyes, I am asking for longer term health of my eyes? Any experienced people please answer..

You can use the Filter+ option from "More" settings of dark reader to reduce it a little: https://imgur.com/a/fNM1og9
before
after