It is advised to wear your SleepSpec for two hours before you go to sleep. There are studies that show that blue light in the evening disrupts the brain's natural sleep-wake cycle causing a chemical imbalance. The sleep-wake cycle is important for the optimal function of the human body. 

In our brain there is an 'internal clock'. That clock regulates the body's circadian rhythm.  This derermains when our bodies are primed to stay awake and be productive and also let's us know when we feel tired and when it is time to go to sleep. Our internal clocks are operated by using certain enviromental factors such as blue light. 

During the day, blue light helps us stay alert as well as improve our preformance and mood. However at night blue light is not a good thing. Blue light at night tricks our brains into thinking that it is still day time and thus the body does not prepare for sleep. 

When it starts to get dark at night, our bodies should produce the hormone melatonin, this then signals to our bodies that it is time to go to sleep. However by us exposing ourselves to artificial blue light (think laptops, TV's, cellphones, white light from light bulbs etc) we are suppressing the production of melatonin. Which effectively reduces both the quantity and quality of our sleep. 

An easy way to remain functioning in the evening without forcing a 'black-out' is to wear SleepSpec. The amber lenses effectively block out all blue light so you are able to carry on with your routine without disrupting your body's rhythm. By wearing SleepSpec for two hours before going to sleep, the body will have produced sufficient melatonin to ensure a quality nights sleep. 

So is there any benefit to wearing SleepSpec for more than two hours? Dr Robert Daniel, the innotive mind behind SleepSpec, and he said that there are no benefits to wearing the SleepSpec shades or more than 2 hours, as the chemical cascade that takes place to produce melatonin only takes that amount of time. There is, however, absolutely no problem with wearing them longer. Rather wear them longer, than take them off too soon. So if you are planning to go to bed at 10.00pm and put your glasses on at 8.00pm, and then find that you are actually only going to head to bed after 11.00pm, just keep them on until you go to bed, and take them off in the dark as you normally would.