aka eyeteeth
Eye teeth are synonymous with the canine teeth in humans. Mammals possess 4 of these, 2 each in both the lower and upper jaw. From the center of each jaw outward (in human dentation) are located 2 central incisors, 2 lateral incisors, 2 cuspids (those of the upper jaw being the eye teeth), 2 1st premolars, 2 2nd pre-molars, 2 1st molars, 2 2nd molars, and finally 2 3rd molars (wisdom teeth) for a total of 16 teeth in each jaw.
Eye teeth figure in speech in several terms. The phrase to give your eye teeth denotes the desire for something which one would pay dearly to possess. An example might be "I'd give my eye teeth to have her for my wife."
Another phrase using eye teeth is Being skinned out of your eye teeth, a feat which denotes the guile of the thief in taking something so intimately close, or also to be gulled so completely as to entirely miss the means by which one is taken advantage of.
Eye teeth also are known by other terms such as fangs, dog teeth, or cuspids. Not all cuspids are eye teeth, however. The cuspids of the upper jaw have roots which extend almost to the orbitals of the eyes, gaining the name eye teeth.
Sources:
http://www.phrases.org.uk/bulletin_board/13/messages/1221.html
http://idioms.thefreedictionary.com/give+eye+teeth+for
http://www.webmd.com/oral-health/guide/teeth-birth-adulthood
http://www.bartleby.com/81/6059.html