I'm giving you another method to open your third eye and it's actually very easy. Just follow Shri Mataji's directions in this 9 minute video. I've done it and it's very effective.
https://www.youtube.com/watch?v=fwKd9hUtc4w
The third eye in Sahaja Yoga is known as Agnya Chakra. When you do this self realization meditation with Shri Mataji, you are asking for the divine energy within you to wake up and pass through all the chakras up to Sahastrara. When you do this you will have the tools to explore in meditation a higher lever of awareness. You can also go to the nearest Sahaja center near you and meditate there for free.