Can't tell what part you're talking about. The character's right eye socket has some blockiness there, but looks like it might just be some JPEG artifacts. Might help to paint an arrow to the problem, or draw a circle around it. Did you push the mirrored UVs out of the 0-1 UV space (or otherwise tell RTT to ignore those…
May be some unwelded verts inside the low-res left eye (his left). Or it could be the normals are wonky in there, try a Normalize or whatever the option is in the Normal modifier, can't remember, don't have Max here. Ultimately you might have to re-mirror the mesh, (his) right mirrored to make (his) left. Oh also, could it…