Q From David Aslin: Why on earth would I even dream of giving my eye teeth for something? And why are they called eye teeth — they cannot see! This is a significant topic for me, as my father lost his eye teeth at the age of around 40, and I have just completed extensive oral surgery to prevent the same happening to me. So eye teeth are indeed valuable, at least to me!
A Down the years, a welter of idiomatic expressions have been created to indicate the vastness of a person’s desire for a particular thing or outcome: people have in rhetorical outpourings offered their hair, their right arms, their last penny, their firstborn, their shirts, their last drop of heart’s blood, even their lives and immortal souls. To offer one’s eye teeth is a good example of the type.
The pointed long teeth — also called canines because they look a bit like those in dogs — are called eye teeth because the pair in the upper jaw lie directly below the eyes. Originally, only the upper pair were given the name but later the pair in the lower jaw also came to be called eye teeth.
Why people seize on eye teeth as a dramatic way to indicate their longing for something is harder to get a grip on. If only you were asking about cut one’s eye teeth or cut one’s teeth, I could respond at once by pointing out that the eye teeth are among the last of a baby’s first set of teeth to appear and so to cut them (have them emerge from the gums) implies that babyhood is in effect over. To say that somebody has cut his eye teeth means he’s wide awake and isn’t easily fooled. If you’re cutting your eye teeth (or just teeth) on something you’re gaining experience in a situation you’re new to.
These suggest that eye teeth are especially valuable, because they figuratively embody hard-learned skills and one’s experience of life. The association with eyes results in an even more powerful evocation. To lose them would cause one to be severely hampered, not merely in eating but in everyday affairs.
Do I look like a fool? Barton’d give his eye-teeth to put the halter round my neck with his own hands.
The Story of Kennett, by Bayard Taylor, 1866.