There are some slight changes though. Indeed his eyes seem to move back into his skull, or his brow seems to be moving forward, as mentioned earlier in this thread. I think there is a easy explanation for this, namely, aging, and losing weight (fat). The first must be logical, that your face changes when you mature. The second is quite obvious when you have a closer look at his face:
You can see that
1) The plates and joints on his skull are more obvious;
2) and more importantly his cheek bones are much more obvious.
This means he’s lost some fat in his face. I think this is the cause of some slight changes.