Oculus (architecture)

An oculus (from Latin oculus 'eye'; pl.: oculi) is a circular opening in the center of a dome or in a wall. Originating in classical architecture, it is a feature of Byzantine and Neoclassical architecture.

It overlaps in meaning with an œil-de-bœuf window, from the French, or simply a "bull's-eye".^[2] These are relatively small windows, traditionally oval. The term is increasingly used for circular windows, but not for holes in domes or ceilings.

A horizontal oculus in the center of a dome is also called opaion (from Ancient Greek ὀπαῖον '(smoke) hole'; pl.: opaia).

^ Bresc-Bautier, Geneviève (2008). The Louvre, a Tale of a Palace. Musée du Louvre Éditions. p. 122. ISBN 978-2-7572-0177-0.
^ "Oculus window". Royal Institute of British Architects. March 27, 2014. Archived from the original on March 27, 2014. Retrieved 24 January 2014.

[1] Bresc-Bautier, Geneviève (2008). The Louvre, a Tale of a Palace. Musée du Louvre Éditions. p. 122. ISBN 978-2-7572-0177-0.

[riba-2] "Oculus window". Royal Institute of British Architects. March 27, 2014. Archived from the original on March 27, 2014. Retrieved 24 January 2014.

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