Suddenly, with a roar like that of a waterfall, I felt a stream of liquid light entering my brain through the spinal cord. After having been engaged in meditation for many years, Gopi Krishna had his first Kundalini Awakening at the age of 34, which he describes thus in this video
The third eye is not really a part of the physical body. It is part of the second body which is etheric body. Your etheric body is a body which is similar to your physical body over which it is superimposed, it has a corresponding spot in the physical body, but it is not part of it, so far the closest reference scientist discovered on psychical body is the Pineal Gland.