People often ask me, because I have the ability to "see" things, how they can develop this type of inner vision. One must first understand that there are some who are born with this gift. Even so, if one doesn't do their work in developing an understanding of the gift and how to use it, then you won't be able to interpret what it is you see. For example, I can see the aura energies and the chakra energies and the meridian energies and so on, but if I had not put YEARS of learning into this ability, I would have been useless in knowing what to do with what I was seeing. So for a person to expect in any way that just by opening up the "third eye" they will have it cased is like telling anyone who can hold a scalpel that they are now ready to perform surgery. Yes, when I said years, I meant it. Too often folks open up and begin to perceive and then place all of the interpretations of those perceptions into the old box of reality. This can create chaos, to say the least.
Meditation, and I mean lots of it, will help to open the third eye and then help you practice the perception of what is seen. The first type of meditation anyone should learn (yes, I just should upon many) is zazen meditation. This involves the "emptying" of the mind through breathing so that clarity of vision and perception can enter the visions.
Vision Questing is also important as it takes one out of the familiar and into nature and tests one's endurance, thus busting up a lot of perception dogma. This makes us experience, instead of expect. When we expect anything, we create that expectation. When we allow ourselves to experience it, then we learn on a deeply intuitive and authentic level.
Energy healing techniques also serve well to help the overall adjustment of the inner vision and the rest of the energy system while the development of the third eye unfolds. This is gentle and gradual and does not usually have anything "erupt" from within in an unmanageable way. The purpose of the energy healing techniques is precisely to allow the unfolding to be gradual, not rushed or pushed.
I encourage folks to start not with one or the other of these three suggestions, but with all of them. When working in tandem with each other, the overall effect of these three different styles is quite remarkable.