AN EXPLORATION OF ART HISTORY
Oculus: The round central opening in a ceiling of a dome. Also, a small round window in a Gothic cathedral.
The Pantheon was a revolutionary design that used concrete for both the buildings material and for shaping the architectural elements. The oculus is located at the center of the dome, opening 30 feet in diameter. It is the only light source in the interior. There is no glass in the oculus so when it does rain it comes into the building. However, the interior has a draining system so the water can be dispensed of. The dome of the Pantheon is very heavy and in order to lessen the weight architects had to find a way to make the dome lighter without weakening the structure. Coffers, sunken decorative panels, were used to lessen the weight of the dome while creating a pattern and rhythmic design throughout the dome. Originally the Pantheon was a temple where any religion could be practiced however, it soon was converted into a Catholic church.