Rebbe Nachman taught "Falsehood is damaging to the eyes, both physically and spiritually. Falsehood damages one's vision, and damaged vision creates distorted images. Falsehood fools people, causing a large object to appear small or a single object to appear as a double or multiple image.
Truth, on the other hand, is unified [it is nothing less than the stamp of G-d's Absolute Unity]. While truth is multi-faceted, it is - and can only be - one.
Falsehood is a direct affront to G-d's Providence. When we lie, we are in a sense pushing G-d out of the way in order to have our own way. In response, G-d acts as though He is turning His eyes away from us. The only way to re-establish our connection to G-d is through truth. Only by speaking truth, believing in its power and living it, can we restore our vision, refocusing on G-d and His Divine Providence. His direct supervision over us is then restored in even greater measure.
Rebbe Nachman teaches that if you want to attain the level of the World to Come, even in this world, just close your eyes. Gently withdraw your mind from all that is going on around you and move yourself into another dimension. The more you "close your eyes to this world", the more you will attain true spirituality and bring the essence of Olam HaBo into your life.
This is the secret behind closing our eyes and covering them when we say the Shema prayer. Up to a certain point the world reveals G-d. Beyond that point however, that very same world obscures Him. We therefore close our eyes and cover them with our hand when we recite the beginning of the Shema, in order to break through the facade of this world to reach towards the Unity behind it.
Source: "Anatomy of the Soul" - Chaim Kramer - from the writings of Rebbe Nachman of Breslov