To take the conversation to its natural extension (and not necessarily the way you need to go) ...
There are people who view light deprivation as a tool, or maybe just something to handle, in the sense of winter dormancy. I have no personal experience with this, but various folks on the forum have to overwinter their plants indoors and don't have a bright, warm location. So they find the brightest one available, maybe by a window in a basement or attached garage where the temps are cooler but not actually cold, and reduce the watering nearly completely for months. Most succulents or cacti will respond to this by slowing their own growth and going to sleep. You can call it induced dormancy, or various other names, but the principle is to coordinate darkness, coolness, and relative dryness and then reverse them in a coordinated fashion come late winter or spring.
So darkness is not necessarily going to kill your plants if you can convince them to go to sleep for a while, but this is not a trivial thing to accomplish, and I have much respect for the climate-limited people here who have come up with tricks to make it work.
