Normally I hear people saying "You should have quality sleep". I didn't actually feel and experience that until last week. Few months back, I replaced my zero watts bulb (Apparently it is 12 watts bulb, check out here). Earlier I had Blue colored one, But I got the plain colored one as a replacement. I replaced the bulb and everything was fine. I normally switch on that bulb during the night and sleep. Initially I didn't realize any change, But in the later days, I realized that even if I sleep for 8+ hours, my eyes were straining during the day time. I thought it may be due to the tiredness of work, travel on Bangalore roads etc. One day I suddenly realized that long long ago, someone told me that my eyes are open slightly during my sleep. I started thinking on those lines and realized the plain colored zero watt bulb provides more light during the night. As I normally open my eyes slightly during sleep, I guess I strained my eyes during the sleep by closing it forcefully to avoid the light, which is the root cause. Then, I switched off the zero watt bulb and slept for few days, the quality of sleep improved a lot and now I sleep at least by 1 hour less than what I used to sleep before, get up early without alarm and my eyes doesn't strain during the day time. So, I really felt the quality sleep :)
Now, I started researching about further improving the quality of my sleep by thinking and discussing with friends. Following mind map conveys all about getting quality sleep.