We have been commanded to recite this Dua regularly. Shayikh Sadooq narrates from Abdullah bin Sinan who says that Imam Sadiq (a.s.) said, "After this a time of such doubt will befall you that you will be without the visible signs and a guiding Imam. And no one shall be able to achieve salvation from this except those who recite "Dua-e-Ghareeq." The narrator asked what this Dua was? Imam (a.s.) replied, After repeating 'Muqallebal Quloob' the narrator added the word, 'Wal absaar' (and the vision). When Imam (a.s.) heard this, he said, "Indeed Allah is the Who changes the hearts and vision, but you recite the Dua as I have said." (Kamaluddin Vol. 2 Pg. 351)