A tunnel incarnates your interior world. For this reason, if you dream of a tunnel in which there is only darkness, it means that you should pay attention to your feelings to get out. Your existential distress is keeping you from seeing the light. If, in the end, you are able to glimpse a flash of clarity, it indicates that you will overcome the obstructions on the way through your strength of will. Your conscience is amplifying your range of action. (See light , black , and bridge )
Gallery of dreams
Reading in dream
Sometimes you will not be able to differentiate lucid dream. If you want to be sure, try reading a simple sentence, if you are able to read then you are in wakeful stage if not you are in lucid dreaming. Studies show that you cannot read while dreaming or you will not find the repeated sentences one more time.
Types of sleep
There are two types of sleep that most of the humans undergo - REM and NREM. REM refers to the Rapid Eye Movement and NREM refers to Non-Rapid Eye Movement. Every individual will alternate these two types of sleep. Non-REM sleep will occur for a short period of time in the first stage of your sleep followed by the REM sleep. Dreams occur during the REM stage, where it lasts for 20 minutes. According to a researcher, J. Allan Hobson, dreams that occur in REM stage are usually forgotten when the individual wakes up. Studies conducted on patients during sleep shows that the frontal lobes in the brain, that are responsible for storing information, are inactive during the REM stage, which is the main cause for forgetting the dreams. Studies also show that this is the stage where you have the most intense dreams.