I bought a light that plugs into the USB port on the Chromebook/laptop. It was a £2 / $3 affair off eBay which I bought for those odd times when I’m trying to work on the Chromebook and I can’t / won’t have a mains lamp or light on.
In short…… it’s crap. The output is too narrow and focused. It really needs to be a more spread out light and ideally from over the top of the display and not the side like this one (the flex / lead isn’t long enough to loop it over the back of the display so it has to sit off to the side which means that your own hands cast shadows and defeat the whole purpose of buying it….. I guess it’s better than nothing).
What really needs to happen is for ALL keyboards to be backlit.