Mains or USB powered reading lamp?

I get very little sunlight in my home, and I prefer to have quite subdued lighting in general, which is however unsuitable for reading books. My eyesight under dim lighting is rather poor, and I am unable to read even standard sized print without straining my eyes very quickly. Howver, I have no problems reading even very small print under direct sunlight.

What are the options for a decent quality reading lamp, either USB or mains powered? Besides continuing my language studies I have recently started studying linguistics, and it is important that I can not only distinguish between different characters and IPA symbols, but also various diacritical marks. That obviously means that colour rendering isn’t the most important factor, but I definitely don’t want to end up with some LatticeBright or other LED with an aggressive cold blue or green-tinted bean. A dimmer would be a nice option, but if there is something that fits all my other requirements, I’d be willing to opt for something with either a single or multiple stepped levels.

Has anyone found something in this department that they think is a winner?