I believe the tool you are refering to is similar to a hollow ground punch. *The tool is ground similar to a nail set punch with a dimple in the center. *Look at the woodcraft.com site and search for eye punch. *You can purchase a whole set from 2mm all the way up to 6mm.
[move]A small snip from woodcraft.com web site------------------[/move]
Handled Carver's Eye Punches
Creating life like, round eyes in wooden faces is no longer a 'pain in the hand!' Our new improved carver's eye punches now include a traditional style, palm handle for ease of use and improved control. Use on your carvings after the eye brow, cheek, and nose portions have been defined. Simply position the proper sized eye punch at the eye location and push while rotating the palm handle. The result - a perfectly round, curved surface eye, ready for enhancement with a carving knife or paints. Overall length approx. 4-1/2', for use on wood only.
Oval and Flat Carverıs Eye Punches. Developed with Tom Wolfe, and popularized in Tomıs many carving books, these eye punches will enable you to create oval animal eyes and half closed (flat) 'sleepy' caricature eyes in seconds. Smaller size flat eye punches can be used with a larger 'round' eye punch to create a detailed eye/pupil effect quickly and easily. Palm handles fit your hand nicely and allow application of pressure without hurting your hand. Overall tool length approx. 4-1/2'. USA.
[move]---------end snip[/move]
The link is
http://shop.woodcraft.com/woodcraft/...355&pf_id=
127118&mscssid=6GT8D2AXNTJK9H1AUXA1FEXV04SADKP B&Gift=false&Giftid=
[move] *

[/move]