Can you tell us where your focus target was? I mean the one the camera used. It will be a red rectangle somewhere on the image and can be seen in Canon's DPP software if you don't remember clearly. That may help. If the lens was definitely auto-focusing on the right eye, then it seems your lens is front focusing, which would exacerbate the blur on the back. The good news is that your camera has AF Microadjust, so you can fix it yourself!


It also occurred to me that the reason for the appearance of front focusing could be that you were shooting at a significant downward angle, which would tilt the focal plane, and in this case in an undesirable (to you, at least) way. If this is true, then the lens may or may not be mis-focusing at all.