Why is this?

We know that you arn't meant to blink when a weeping angel is near, so how come now Amy specifically cannot open her eyes, and from the trailer she does open her eyes.

Please reveal more if anyone knows

I don't know...my guess is because she has looked into the eyes of the angel and is turning to stone already

As "half angel" already maybe if she looks she will turn to stone, maybe it makes her immune to the don't blink rule

She can probably open her eyes at some point....I doubt she will be running around the rest of the series with her eyes shut

My current theory is that with Amy becoming more and more like an angel (well in her mind) if she looks at a weeping angel she'll be quantum locked forever just like the Angels in Blink.

Amy has become an AntiAngel.

If Amy the AntiAngel looks at someone from a certain Angle then they turn to Stone*

The Doctor has to keep an eye on where Amy is standing compared to everyone else if she moves into the AntiAngel Angle then he shouts for her to close her eyes till she has moved out of the AntiAngel Angle.

*This of course ties in with the Greek mYthology that is supposedly all over the series.

didn't the Doctor tell her during that trailer that she had to keep her eyes closed - if she opened them she'd die? I don't think that was for the scene of her walking through the Angels with her eyes closed but it may have something to do with it...

A work-mate of mine said that, because you see an Angel reflected in Amy's eye in the trailer, then "that which holds the image of an angel, becomes itself an angel". Maybe that's why she's turning to flesh and stone?

Or there is angels creating each other from her eyes,

Yeah... not unusual for a scene in the trailer to be matched with a voiceover from another scene... otherwise, I'm flummoxed!

Im wondering if this will mark Amy for the rest of the series, unless there's a defintive answer in the ep.