Clairvoyance – that of mediums is different from that of a true Initiate

The clairvoyance of mediums is more or less always restricted to the astral plane. When you ask a medium to reach far distant regions to answer questions of a spiritual or cosmic nature, most of the time they are not able to do so. Well, clairvoyance that does not serve to elevate human beings is of no interest to Initiates. This is why Initiates do not linger on the astral plane, and even keep their eyes closed as they cross these regions.
True Initiates do not seek to develop mediumistic powers. They work only on purifying themselves, on cultivating wisdom, love and self-control in order to reach the summit. And once they have reached the summit, the substance of their being is so purified that it is imbued with the very quintessence of the Universal Soul. This quintessence, on which everything is recorded, gives them the ability to see and sense whatever they wish to know. And so through their work, they acquire not only power, but clairvoyance as well.*

Omraam Mikhaël Aïvanhov

* Related reading: Looking into the Invisible, Izvor No. 228, Chap. II.