Why do you want to use your third eye?
Ok a dumb question, meditaion is the best way, it's nice and easy, like slidding into your bed on a cold night, when you've got your electric blanket on, yes I'm a little cold
People might say use drugs, but this is like being electricuted by that nice warm blanky and distroying a peaceful evening, seriously, don't do it, my experience started like this, rather than being like a strange pressure durin a tranquil state, it was my head spliting down the middle like a fault line, I nearly lost my mind because besides the large amounts of drugs I was using, the opening of the thrid eye causes it's own extreme conciquences, the two together is, well, like a real but wierd version of the Blair Witch Project being filmed in your own mind,
That would be your crowbar version, It might work for some but..
You don't actualy see through this eye, well I never have, not like you see through your physical eyes, but it's effects can been seen with the physical eyes, not because of them though, this perception occurs in your mind to the best of my knowledge,
Although it was also been known as the minds eye, sometimes you can see things like on a projector in your mind, but this has been rare with me, I find it hard to distinguish between this and imaginary visualisation, exept for when it's realy strong,
I don't think that your world will change over night, it's not like a instant sage recipy, you wont be given more than you can handle at a specific time, but will progress naturaly, which is best
But I wouldn't trust me, I think I'm right of corse and wont lye, but somebody with a lot more experince will help a lot more, read some yoga books, I recomend Swami Rama Tritha, Swami Vivekananda, and the Kriya Yogis, also the book Kundalini Tantra by Swami Satyananda seems very good, I haven't read a lot of it yet though, even the Bible seems to mention it
"If your eye be single, then you whole body be full of light" KJV
Check this out, I'm not sure if you'll like it, but it's a start
http://yoganiketan.net/