Part of the problem may be the way the M3 EyeSocket material is UV mapped. Here is the EyeSocket UV map shown over the M3 high res texture. See the part on the right? That is part of the eye socket but it gets it's texture from the part of the face just to the right of the eye area. That part that sticks out is the part of the eye socket on the edge near the lacrimal. So whatever texture you have in that part of the face is actually duplicated in the corner of the eye socket. Also, because of the angle of the eye socket, it will tend to be shadowed, so have a darker edge.