Statues, decorative columns, triangular pediments, niches, and other architectural details alternate around the circular interior of the Pantheon; a polychrome marble floor and a dome with recessed panels still create a dazzling effect.  The most unusual and striking effect is created by the oculus, or eye, 30 feet in diameter, which allows sunlight to sweep the interior to create constantly changing patterns of light and color.  The Pantheon's proportions are very carefully calculated and contribute to its air of balance: the height of the dome is 72 feet, one-half the diameter, which is equal to the total height of the building.