A lot of monkey-minds claim on the internet, and in person to me, that their third eye is open and that they feel their Kundalini is risen to the third eye because they feel vibration there.
Please note that the astral spinal pathway through which the Kundalini rises is actually a multi-channel pathway. Within the Sushumna channel, there is the more refined Vajrani Channel, within which is the further refined Chitrani channel, within which is the most refined Brahmi channel.
Feeling vibrations and occasional intuitive visions don't mean that one has refined oneself to the Brahmi channel - which is where one can call oneself Self-Realized at a given chakra level. And it is not so easy!
So for the benefit of the monkey-minds, here is the yardstick that one should use to see where you are at:
1) You have entered the Brahmi at the Anahat (Heart) Chakra if you hear the "sound of slience" in your right ear or in the head. It is not the sound of AUM, it is the sound of TAT. "Hearing" this sound constantly means you have become unconditional in your Loving.
2) You have entered the Brahmi at the Vishuddhi (Throat) Chakra if you have mastered ("shuddhi") five senses - Touch, Taste, Sight, Smell and Hearing i.e. you are not craving for someone's touch, you are not craving for anything tasty, you are not craving for any beautiful or sensual sight, you are not craving for good smell and you are not craving for people to say good things about you. And when I say not craving - I mean completely not craving. This is when one becomes "indra-jeet" or the "Master of the Senses". However, three aberrations still remain: Fear, Anger and Sex (as an impulse without lust for touch).
3) You have entered the Brahmi at the Ajna (Third Eye) Chakra if you have no fear and no anger left. Again, completelely no fear and no anger at any time. Lord Krishna became angry only once in the Mahabarat where He lifted the wheel of a broken Chariot because his friend Arjuna was struck by Bheeshma's arrow. Lord Krishna was at the third eye in his waking consciousness. One impulse (not craving) still remains - Sex (as an energy impulse without lust for touch). Sex impluse is "hard-coded" in each chakra below crown to keep the creation going. No running away from it.
4) You have entered the end point of Brahmi and have pierced the Brahmrandhara at the Sahasrahar (Crown) if you have no impluse for Sex and you have all the qualities of 1,2 and 3. You want to be in the Self - and find joy and completeness in the singularity of your Self. Understand the root chakra is one polarity and crown is another. When polarity develops in the crown, true Brhamcharya is established here.
When you are at (4) you will have to descend to the Third Eye (3) to indulge is any kind of relationship.A person at (4) can move up and down any chakra but again there is no impulse unless he chooses to generate it. There is a very clear distintinction here. Infact, this is when the person becomes Shiva - both a Maha Yogi (renunciant) and a Maha Bhogi (indulgent).
There are astral powers or "siddhis" that get generated at 1,2,3 and 4 but what I have presented is a clear yardstick that anyone can use.
So when your ego tries to make you feel good about the vibration in your heart or third eye, gently direct it towards this yardstick.