The calm, roughly circular center of a mature tropical cyclone is called the eye.
The eye forms when air sinks in the storm’s center while the strongest rising air and winds surround it in the eyewall. Because descending air warms and dries, the eye can have lighter winds, clearer skies, and less rain than the rest of the cyclone. However, it is not always completely calm or cloudless.
The eye is typically surrounded by the eyewall, a ring of towering thunderstorms containing a tropical cyclone’s most destructive winds and heaviest rain. As a storm strengthens, its eye may become more clearly defined. Powerful cyclones often have relatively small eyes, although size varies considerably.
A dangerous mistake is assuming the storm has ended when the eye arrives. The opposite side of the eyewall follows soon afterward, bringing winds from a different direction. Tropical cyclones are called hurricanes, typhoons, or cyclones in different regions, but all can develop an eye.