Do tornadoes have eyes?

Dear Tom,
My son is studying tornadoes and hurricanes in his fourth-grade science class, and the following question has caused some controversy and discussion: Do tornadoes have eyes?
— Denise Perkins
Dear Denise,
Tornadoes are small-scale storms that produce the fastest winds on Earth. Single-vortex tornadoes (tornadoes that consist of a single column of air rotating around a center) are theorized to have a calm or nearly calm “eye,” an area of relatively low wind speed near the center of the vortex. The theory is actually born out by Doppler velocity radar observations. A few eyewitness accounts also exist, though they are rare. It should be noted, however, that the calm or nearly calm air in the eye of a tornado is actually moving with the speed at which the tornado itself is moving.