The various Prophecies imply that Mat has to cut his left eye out, as said e.g. Egwene's "nasty" Dream about "Mat, placing his own left eye on a balance scale." But also her Dream about "Mat throwing dice with blood streaming down his face, the wide- brim of his hat pulled low so she could not see his wound, while Thom Merrilin put his hand into a fire to draw out the small blue stone that now dangled on Moiraine's forehead." Min saw around Mat "an eye on a balance scale" as well. And of course the Aelfinn telling Mat that he has “to give up half the light of the world to save the world”.

In KoD Mat even muses that the Finn might be connected to him via his eyes.