moved from Fruits of Lucidity to General Lucidness 
Has anyone ever done it?
You can use lucid dreaming to repeat an activity if that counts as “studying”. However, since you cannot get any external input when you’re dreaming, you can’t study from a book, for example.
So you can study stuff you already know, like revise it?
Most certainly, if you can recall it. (And if you’re lucid enough)
Well Uzi, welcome to the forum, first of all! I hope you enjoy your stay here.
Now, to your question - There have been very few experiments around our community with learning in lucid dreams. However, there are a few ancedotes about it - one of the most famous one tells that you can “revise” what you already know, greatly improving your useful knowledge. That specific instance was about maths.
Outside sources have proven, more or less, that you can’t study while sleeping simply by hearing the material - however, I have yet to see a study which had its participants hearing the material in a lucid dream.
Studying while lucid dreaming, though, might help by enhancing your confidence, as well as priming your mind to the subject (Though the later is only important if you test your knowledge [Or study the subject] soon after waking).
One last thing - Lucid dreaming might help you revise material you didn’t realize you know - such as material long forgotten, or material you keep sensing daily without taking note of it.
To sum it up: Go ahead and try! And if you feel you’ve got something solid to make a research about, you can use ld4all as a group of lucid dreamers, ready to experiment.
This is somewhat related to studying in dreams -
When I was studying abroad in Australia, I had a very interesting English class. My teacher was very into chorography and consciousness. Probably the most interesting teacher I have ever had. Anyway, I had to write a research report and I had NO clue what to write it on. Before I went to sleep I asked my dream to show me a topic. That night I dreamt that I had an amputated arm and that I could still feel the phantom limb. The next morning, I searched around online for stuff about phantom limbs and I found out about a disease called BIID. This was the topic of my paper, which basically asked the questions of where does the body end and the mind begin? Can the scalpel shape the body? The mind? And more. If I had never asked my dream for an answer, and I had never LISTENED to that answer, then I would probably have written a report about something else not as interesting.
I got an A+ on the paper.
Yes, indeed, dreams are an excellent source of creative material, since they are so random in nature. Dreams can be referred to as “very active brainstorming”. However, after brainstorming there is always a refining process to eliminate the bad ideas, so don’t expect every dream concept to be a useful source of material.
I agree, and, because I have had a 12.9+ comprehension level since 1st grade, I milk all the material out of anything I read…so, why not have the boring history lesson during class, then, that night, enter history! Watch Paul Revere! Dump british tea into the harbor, ect.
I don’t think that would work.
With all due respect, Magic Qwan, if that is the way you study IRL you really need an extreme studying makeover. 
History does not have origin in your mind and dreams.
I said that dreams are an excellent source of creative material, imaginative original work not present in real life.
You do have a point, but, Magic Qwan did say he would have the lesson during the day, then only relive the information at night. Logically, dreaming would be being used as an aide to memory in that case. I’m sure for certain types of learner, being part of a scene will help make the details stick. The only thing that could be a problem is if your mind fills in the blanks and introduces inaccuracies.
I don’t see a reason to limit ourselves by thinking that you can’t learn something totally new. This is a new frontier, a new experience, probably you can know whatever you want to know, probably consciousness is not singular (yours alone) but is connected with that of others thus allowing you to know things that you never encountered. There are so many probabilities and so many outcomes we cannot possibly say that X is impossible.
What I am saying is we should not start limiting ourselves and putting our own rules to things that we don’t yet understand, we should experiment, and push past gates and locks we put on ourselves. Does that make any sense. 
Please, don’t do it… i mean like, seriously xD. Rest at least when you sleep cough. When you’ll be lding imagine nice ld-spa ;] or whatever, don’t study.