Seeing the unseen starts by the good vision during sleep then followed by inspiration from God (Glory to Him), then the light of insight, then revealing secrets, watching and others.
God grants man means to achieve available knowledge and sciences, as there are apparent tangible types of knowledge and hidden types of knowledge that can’t be recognized by senses, so God made a certain suitable means for every type of knowledge, God says about them all:
“For every act of hearing, or of seeing or of (feeling in) the heart will be enquired into (on the Day of Reckoning).”
Surat Al-Israa’, Verse 36.
Understanding tangible natural phenomena and collecting knowledge and sciences of this life is by watching, seeing, reading or perusing and this can be got by sight, or by receiving knowledge from scientists, experience from experts and wisdom from wise men and this can be got by hearing. These two senses, sight and hearing, are the basis of getting all types of knowledge of this life, but the unseen is what we can’t see by the naked eye or hear by the ear or touch as all the senses are unable to recognize it but the heart, only the heart by God’s support can realize such divine invisible secrets, the heart has an eye sees the divine unseen secrets, it also has an ear that can hear the sounds of spiritual meanings, it has a tongue by which it talks to the divine highest facts. If man responds to the apostle sent by God, chastens his soul and purifies his heart by remembrance of God, the mist is removed away from the eye of his heart then he can see by the light of God what we can’t see. God says about this:
“Truly it is not their eyes that are blind, but their hearts which are in their breasts.” Surat Al-Hajj, Verse 46.
God also can remove the cloudiness away from his inner ear so that it becomes an aware ear that listens to the sounds of superior facts, God says about such people:
“In the case of those who say, "Our Lord is Allah,” and, further, stand straight and steadfast, the angels descend on them (from time to time): "Fear you not!" (They suggest), "Nor grieve! But receive the Glad Tidings of the Garden (of Bliss), which you were promised! "We are your protectors in this life and in the Hereafter: therein shall you have all that your souls shall desire; therein shall you have all that you ask for! “A hospitable gift prepared by (God) The Most-Forgiving The Most Merciful!” Surat Fosselat, Verses 30, 31, 32.