This sort of helmet always has the eyes higher than you might expect. There are two reasons for this. The first is that the skulls are very round, and there is only a sort of minimal spacing between helmet and head on the top. The second is that the chins are very sharp, and there is a lot of internal space there.
A side view of this helmet would tell more, but I am pretty sure it's OK.
Mac
Robert MacPherson
The craftsmen of old had their secrets, and those secrets died with them. We are not the better for that, and neither are they.
I see. I expect to see the eye slot in the vertical center of the helmet so the whole proportion thing tricks my eyes then. I will add pictures of some of the other helmets that looks odd to me when I bump in to them..
[more complicated way of saying what Mac said] A key factor that misleads the eye when dealing with helms in this style is their extreme width. They are not dead round, but they give that impression when looked at from above. This extreme width effectively makes the distance between occularia and the top of the skull look shorter. If you distort the image so it looks narrower, the skull will look less shallow. Oh, and what Mac said about the chin, too.