Oculus
These openings in a ceiling, dome or canopy really get around
An oculus was originally a round opening at the center of a dome designed to bring light from above into a space. The most famous oculus is at the Pantheon in Rome. Since then "oculus" also has come to mean any round opening in a ceiling. One of the fascinating things about an oculus is the circle of light created and how that circle moves about the interior during the course of a day.
An oculus can be used in an exterior canopy as a way to brighten an entryway. The location of the light beam cast by the oculus will shift throughout the day as the sun moves across the sky.
An oculus is also a great way to bring light deep into the interior of a home, especially when it's located above a vertical element, such as a stairway.
An oculus is a great way of introducing a shaft of light that enlivens a space.
It may also provide a glimpse of the sky above.
A round opening in a ceiling allows an abundance of light to fill a room and can become part of the design's motif.