HEAD
HEAD: The skull is slightly rounded, but without dome or peak; it should appear flat because of the high placement of the ears.
EYES: Large, round and set well apart; color a warm, very dark brown, giving a lustrous, limpid look. there should be slight cushioning under the eyes, which contributes much to the sweet, gentle expression characteristic of the breed. Faults: Small, almond-shaped, prominent or light eyes; white surrounding ring.
Below is a picture of a puppy at 10 weeks of age. She has one non-pigmented eye shown on the left side and one pigmented eye shown on the right side. You can clearly see the 'white' of the eye in the eye on the right side, but it has color in it. Particolor puppies are born with the 'whites of their eyes' white and the pigmentation shows up later--usually starts coming in by 6 to 8 weeks of age. If it has not started at all by 12 weeks of age, it is unlikely to ever come in.

NOSE: There should be a shallow stop and the length from the base of stop to tip of nose should be at least 1 1/2 inches. Nostrils should be well developed and the pigment uniformly black. Putty, or "dudley" noses and white patches on the nose are serious faults, as are small,pinched nostrils.
MUZZLE: Well tapered; mouth level; lips well covering. Faults: Sharp, pointed or snipey muzzle. Full or pendulous lips. Flesh marks, i.e. patches of pink pigment showing through hair on muzzle.
TEETH: Strong and even; preferably meeting in a scizzors bite, although a level bite is permitted. Undershot mouths are greatly to be discouraged; it should be emphasized however, that a slightly undershot bite in an otherwise well-balanced head with the correct, sweet expression should not be penalized in favor of a level mouth with a plain or hard expression. Faults: weak or crooked teeth, crooked jaws.
EARS: Set high, but not close, on top of the head. Leather long with plenty of feathering and wide enough so that when the dog is alert, the ears fan slightly forward to frame the face.
The following 4 pictures are of two Cavaliers, both as adults and at 8 weeks. These pictures depict very nice Cavalier heads showing the proper ear set, the skull appears flat because of the placement of the ears, nice round eyes with proper cushioning beneath the eyes, muzzles not too long nor too short, and the nice plushy muzzle with lips well covering that give the breed its sweet and gentle characteristic look.

The next 4 pictures of two Cavaliers, both as adults and at 8 weeks, depict a head that is not as nice as those above. Both have the proper ear set, the skull appears flat because of the placement of the ears and have nice round eyes. The Cavalier on the right is lacking the cushioning under the eyes but the one on the left clearly has the cushioning. Both are lacking the proper muzzle--the muzzles being a bit too narrow, lacking plushiness, and being a bit too long. They could both do with more height of skull as well. Because of this their expression is just not as sweet and gentle as those above. Not horrible heads, but not great heads either.
I hope to get pictures of some really awful heads, as well as pictures of improper ear set--too high and too low, almond-shaped and prominent eyes, dudley nose, pendulous lips, etc.