I would first of all like to say that this is my first theory I have written, so forgive me if I ramble or repeat myself.

Many people have expressed the idea that Mat accepted wine from Ba'alzamon, and therefore his eye could be used for the Forsaken or Dark One to look through. They have backed this up by saying that we never get to see Mat's dreams and we only see Rand and Perrin refusing wine in their dreams. However, after Rand dreams of being offered the wine and refusing in Baerlon, he meets Mat out in the streets. They both decide not to tell Moiraine of their dream, but to tell Thom. Mat tells the dream to Thom and Rand thinks:

“...each dream was a little different, he thought. The major part of the dreams was the same, though.”

From this, I think we can deduce that Mat did not accept the wine, as this would have been a major difference, and did not miss it out because otherwise Rand would add it in later when he says his part.

Now, I think that each of the three boys had a dream where their eyes were taken. First of all: Perrin.

“‘I mark you mine!” He flung out his clenched hand as if throwing something; when his fingers opened, a raven streaked at Perrin's face. Perrin screamed as the black beak pierced his left eye.”

This is from the dream Perrin has in the Tuatha'an camp. We know that the boy's dreams are in Tel'aran'rhiod from the ways that the light is described by Rand in his (coming from everywhere at once, etc, etc). This means that whatever happens in their dreams are true. This means that although the raven did not take Perrin's physical eye, they have in some way “taken his eye”. Also, ravens are often used by the Dark one to see through their eyes, so is there a more appropriate creature to take the boys' eyes?

When he wakes, he, Elyas and Egwene decide to leave. As they are leaving, Perrin thinks:

“Perrin did not want to think about his dream. He had though that the wolves made them safe. Not complete. Accept. Full heart. Full mind. You still struggle. Only complete when you accept.”

This gives us a reason to believe that Perrin can be safe once he accepts the wolves.

When Perrin and Egwene are caught by the Whitecloaks, Hopper attacks the Whitecloaks. In this one moment, Perrin becomes one with Hopper flying through the air. We can see this as fully accepting the wolves into his mind and heart. Robert Jordan then describes how Hopper looks after the raven attack on the pack of wolves:

“A gash down his face crossed the empty socket where his left eye had been.”

Perrin's left eye was plucked out by a raven; Hopper's left eye was plucked out by a raven. I understand this as Hopper took the evil into his eye on behalf of Perrin. This means that Perrin no longer has Forsaken looking through his eye.

Rand has a dream later in the back of Bunt's cart on the way to Caemlyn.

“‘You are mine,' the raven said, and the sharp beak stabbed into his eye. He screamed as it plucked his eyeball out of his head.”

Again, I think that as the dream was in Tel'aran'rhiod, the raven must have in some way taken Rand's eye. I am extremely irritated because I cannot find the next quote I was going to use anywhere. However I know that somewhere near the beginning of book 1, Moiraine tells someone that the One Power gives protection to the user against the Dark One. She then said that for men the taint also weakens them to the Dark One so it works both ways. From this, I believe that from the time that Rand uses the power (perhaps the first time is when he makes lightening strike down Howal Gode in the Dancing Cartman) he is protected and his eye cannot be used by the dark.

Then we come to Mat:

We know he had the same dream of his eye being taken from this quote as he woke:

"My eyes! Oh, Light, My eyes! He took My eyes!"

Now, Mat has no way of countering this. Also, there are many other pieces of evidence that back up the theory that Mat's eyes are being used. There are so many that it is almost impossible to believe it is not true:

Mat exclaims that he would never betray rand, over and over again after rand tries to take them to Toman Head using the Portal Stone. This caused everyone involved to see their lives replayed, so we can assume that mat saw himself betray Rand many times.

Also, when the company arrives at the Eye of the World, Aginor says: “He guided us.”

Moridin mentions that he has spies everywhere, and that some don't even know they are spies- this seems too much of a coincidence just to mention this for the fun of it.

Also, Min has several viewings of Mat, including:

“An eye on a balance scale.”

Also Egwene sees:

“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 the fire to draw out the small blue stone which now dangled on Moiraine's forehead.”

This seems to implicate that Mat will lose an eye to help save Moiraine. We know that Moiraine is somehow trapped by the Aelfinn and Eelfinn, and when Mat went to visit them they told him that he must give up half the light of the world to save the world. This can obviously be interpreted as losing an eye to save the world. As losing an eye seems to be connected with saving Moiraine (who will go on to help save the world), Mat will return to the other world perhaps through the Tower of Ghenjei, and set the price as his eye to save Moiraine.

I think that this makes it all too clear that Mat's eye is being used to spy on what he sees, and how it came to be. Thanks for bothering to read all this and I would really appreciate some replies so I can see whether anyone else agrees with my ramblings.