| Each of the upper study areas has an oculus in the floor revealing its counterpart below. |
| At the centre of the dome is an oculus, a circular hole, which is the only source of light. |
| What could have swayed Capponi away from the plan for an oculus and toward the tall, narrow shape employed by Marcillat? |
| A large oculus brings a cylinder of light down into the main library, bathing the interior in a softly luminous glow. |
| The oculus windows depicted in each of their two cells illuminate the figures with an otherworldly silvery light. |
| The light entering through the oculus at the top floods the space with hypnotic patterns of light and shadow. |
