Are there any ways to change a player’s vision, similar to how nightvision/nausea/blindness changes vision? Or are they hard coded? I wanted to create a “sun scorched” effect that increases exposure on a player’s screen, making it extremely bright. Would this be possible?

I don't know if this is the best way to do it, but you can increase the brightness by changing the gamma value like so:

Minecraft.getInstance().gameSettings.gamma = some value here

 

I think you could find this mod useful to look at: https://www.curseforge.com/minecraft/mc-mods/enhancedvisuals