These will help your eyes.
A good color scheme is the most important thing to use - it will help you quickly identify stuff such as functions, methods, keywords, etc.
- Solarized - a nice blue theme, personally way too much blue for my taste, but very clear contrast.
- Gruvbox - what I personally use, on medium contrast, dark theme. No documentation, so implementations in different editors vary.
- Nord - A low contrast, pastel theme. It’s got great documentation, but too low contrast for me.
- One Dark - based on the atom theme, this implementation has several different versions.
You will want to install a Nerd Font version of your font, just so you can insert icons if you ever need them. Of course, you can also patch your own font if you prefer.
- Iosevka - a nice font, narrow, and tall. Can also be built from source code, using the customizer to plan your build. What I personally use, with a custom build.
- Roboto Mono: Wider than Iosevka, but still has the slashed zero I like.
- JetBrains Mono: A very popular monospace font, with ligatures. However, I find it to be too wide for my taste (plus I like the slashed zero of Iosevka. Also available as a base in a custom Iosevka build.