Scientists tell us that, on average, humans require about eight hours of rest per night. But studies also show that individual needs vary dramatically.
An honest self-analysis can determine if you are already in a healthful pattern or are experiencing a sleep debt. Experts generally agree on these signs of healthy sleep:
* Sleep comes easily without resorting to drugs or fighting restlessness or anxiety.
* You are rarely aware of waking up in the middle of the night, but if you do wake up, you can go back to sleep quickly.
* Waking up occurs naturally at approximately the same time each morning and usually without the aid of an alarm clock.
* Once you are up and going, you feel awake and fairly alert all day.
Practical Points
What about those with occasional insomnia? Some experts suggest these practical steps:
1. Avoid alcohol as well as stimulants such as coffee or tea near bedtime. Many people mistakenly believe that alcoholic beverages will help put them to sleep. However, clinical studies show that alcohol can have a rebound effect and keep you awake.
A smoking cigarette
Smokers have greater difficulty falling asleep
2. Quit smoking. One authority notes: "Smokers have greater difficulty falling asleep, because cigarettes raise blood pressure, speed up the heart rate, and stimulate brain-wave activity. Smokers also tend to wake up more in the middle of the night, possibly because their body is experiencing withdrawal symptoms."
3. Avoid extreme mental or physical stimulation just before bedtime. Exercise promotes proper rest but not if done immediately before trying to sleep. Tackling big problems or mental challenges just before you go to bed can interfere with the relaxed mood often needed to drift off to sleep.
4. Make sure that your bedroom is quiet, dark and, where possible, relatively cool. Regarding noise, consider one famous study of people living near an airport who claimed that they no longer heard the airplanes. When their sleep patterns were tested, their brain waves recorded each landing and takeoff! The researchers concluded that the test subjects averaged about one hour less of quality sleep each night than those in a quieter zone. Earplugs or other methods of reducing noise would have greatly assisted them in getting restful sleep. Some find that white noise (defined as any low-frequency, steady, and monotonous hum), such as made by an electric fan, is especially helpful if there is a need to mask street sounds.
Pills
Be cautious about taking sleep-inducing medications
5. Be cautious about taking sleep-inducing medications. There is growing evidence that many drugs prescribed to induce sleep are habit-forming, lessen in effectiveness with prolonged use, and have damaging side effects. At best, such drugs may be useful for short-term therapy.
Since insomnia can be brought on by stress, it is thought that one key to healthy sleep is making the time just before going to bed a quiet, pleasant period. It may be helpful to set aside the cares of the day and do something enjoyable, such as reading.
Greetings Tur
for now...
I need 8 hours straight sleep or else I am an unhappy person. That's what I have been told. Plus, if I don't get much sleep I get dark circles under my eyes. 
You think that's got any thing to do with sleep or is it something else e.g. wrong size shoes you are wearing. 