I know, that it's off topic to you as you are looking for a solution to lower the light...
Below certain light level our eyes turn into night/evening vision. See out of focus, don't recognize colors properly, but otherwise let us see even just a silhouette of the object in those unfavorable conditions. It's really bad to demand your eyes to read in such mode for prolonged time.
I've been prescribed reading glasses at the age of 34
and it only went up. Eye doctors kept saying, "don't worry, we see it common nowadays that people experience old age vision problems much earlier, about at the age of 30". By a chance I read one day about a study done in Australia (I believe) about the light contribution to vision problems. They have patched the eyes of chickens, introducing slight vision issue, and after a period of time measured the eye refraction. In typical indoor light condition the chickens with the patched eyes developed bad sight. However when the luminosity was at the level of a bright sunny day outdoors the eye patching did no harm to the eye, that is even if the vision was not perfect they eye did not develop the issue further.
I'm 40 and I don't need reading glasses anymore
I've been cured in a matter of 2 years from +1. I just did a radical changes in my life. I have my work place close to the window, in the evening illuminated by 4 x 7W LED. I changed the color schemes on my computer from dark colors to white background, black text and I just make sure it's bright enough so the environment brightness is not disturbing. I don't read in bed. Before sleep, with a dim light, I just watch some movie or listen to an audiobook.
That being said, don't get my rant too seriously
Keep living as usual if you're happy. It wasn't my intention to preach that you cannot not read in darkness. You're the owner of your body