eye
The central roundel of a pattern or ornament. Photo from New York City, New York, 2018. 2. The circular (or nearly circular) central part of a volute, as in an Ionic capital. 3. One of the smaller, more or less triangular openings between the bars of Gothic tracery. 4. An oculus, especially one at the summit of a dome. 5. Appreciative or discriminating visual perception. (Harris, 1977)