no need for youtube videos. the literature on it is quite readable. the basic idea is to expose yourself to as much sunlight or artificial UV-filtered light as possible in the morning within 15 minutes of waking up, and then to taper off your light exposure after noon. studies worked with about 10klm aimed downward at about a 30 degree angle to simulate sunlight. while doing this, you also need to practice superb sleep hygiene, going as far as timing meals and eating specific compositions and compounds at mealtimes. it can also help to use blue-light filtering glasses, as the eyes are particularly sensitive to light in the blue spectrum.
when performed properly, it has been empirically shown to be extremely effective at allowing one to regulate sleep structures _without medication_. however, as these things usually are, it is quite difficult to do properly, and should be guided by a professional
in studies, melatonin was shown to be effective when used in a very specific way. basically, melatonin is produced naturally with the tapering of light exposure by the pineal gland, and typical serum levels are in the 0.25mg range at peak. hence, if you find that your body is not producing melatonin on schedule DESPITE the above, very small dosages (most synthetic melatonin is just metabolized..) in the 0.5mg range about 4-5 hours before your timed bedtime have been shown to sometimes help speed up the process of recovering normal or desired hormonal rythms. Note that I specifically mentioned timed bedtime. sleep hygiene and light therapy call for timing wake-up time, bedtime, and mealtimes, _strictly_, and gradually pushing them toward your desired wake-up and sleep-time.
the summary of all this research is basically that sleep cycles in a normal healthy person are really determined by a few very important things, most importantly light exposure and meal times and compositions. you can use this information to do incredibly bizarre things to your sleep cycles, or to make it more normal. that is, IF you are a normal healthy person. there are a number of what are most likely hereditary disorders in which some people have abnormal responses to this stimuli, and for those people, this regimen can be ineffective or must be modified. hence, if you have serious problems in functioning because of sleep cycle issues, the best course of action is to see a specialist.
