Why use drugs to stay awake when you can use light?

Its exam time, and lots of students will be desperate to extend their hours of wakefulness so they can fit as much study in as possible (or soon will be) and many of them will turn to drugs such as caffeine to keep them awake and alert for longer, however, putting chemicals into your brain is a BAD thing, especially things that speed up the brains processing speeds too much as the neurons begin to misfire and signals don't go where they're supposed to.

But there is a much better way to stay awake, and that, is white light, no chemicals, some people would argue no particles at all! (but then we get into photons vs waves, packets verses continuous energy blah blah) and what causes this wakefulness? our old friend the pineal gland.

The pineal gland secretes melatonin, and as few people know, melatonin fights cancer, but a more known fact, is that melatonin controls the sleep wake cycles of the body,

Normally, melatonin levels begin to rise in the mid- to late evening, remain high for most of the night, and then drop in the early morning hours, so the best time to fight cancer is when you're sleeping, huh, being awake CAN increase your risk of cancer, so there's a down side, but you'll sleep and the risks will level out after exam times.

The reason why melatonin levels alter throughout the day is due to the amount of light, as light affects melatonin production, during shorter, darker days, the body will produce more melatonin and its levels will increase earlier in the day than usual, this change CAN lead to symptoms of seasonal affective disorder (SAD), also known as winter depression, so by staying up longer with this light you reduce your risk of that.

This is due to the darker days and longer night time periods we experience in the winter months, (ever noticed you feel more tired or gloomy on a grim wet day? its not JUST because of the weather, or it is, because the clouds are stopping the sun light)

So, if melatonin increases you become sleepy, this happens at night, so the converse must be true for during the day, melatonin decreases, you feel more awake, when the sun is out, so the best way to feel more awake? Have a very white light in your room.

It is worth noting (but not going into) that different wavelengths have different effects on wakefulness, red light, for example, promotes melatonin production, making you feel more sleepy, white light is the best, but certain wavelengths will have increased/decreased effects

providing you sleep and get SOME REM sleep, your brain will process the information still :) 
 
http://www.ncbi.nlm.nih.gov/pubmed/12004644
www.vivo.colostate.edu/hbooks/pathphys/endocrine/otherendo/pineal.html
http://www.webmd.com/sleep-disorders/tc/melatonin-overview

more interesting than revision xD