Birds and butterflies get caught in the eye. They fly near the eye wall but are unable to penetrate due to the strong winds.
The skycondition and the width of the eye are variable. The eye can be partially covered with clouds or completely devoid of clouds. It can also be completely covered with clouds, in which case, meteorologists say the eye is not visible. A very strong cane will have a distinct and small eye. When you see that on the weather maps, you know that a strong cane is forming. Hugo hit Charleston in Sep 1989 as a Cat 3. The eye covered over 20 miles even though it was a strong cane.