Anulus ocularis
Anulus ocularis vel anulus periocularis vel circulus ocularis in avibus est anulus pennarum perparvarum qui anulum orbitalem circumdat, anulum cutis nudae qui oculum avis artissime cingit. Anulus ocularis saepe est merum ornamentum, et eius color a plumas adiacentbus discrepare potest. Anulus pennarum aliquando imperfectus est, arcum ocularem formans. Conspicuo anulo oculari absente, anulus orbitalis saepe anulus ocularis appellatur. Nudus anulus orbitalis durus aut corporeus esse potest, vel wattle ocularem formare potest. Qui est signum investigatoribus agrestibus utilissimum in multis avium speciebus. Rhynchocyclus brevirostris, 
Hemitriccus orbitatus, et Asthenes palpebralis sunt exempla specierum quae ex ea proprietate vulgo in variis linguis appellantur.

Pinacotheca

Anulus scleroticus
Glossarium vocabulorum avianorum
Iris (anatomia)

Notae

Bibliographia
Birdsley, Jeff. IB 461: Ornithology, External Anatomy. School of Integrative Biology, University of Illinois Urbana-Champaign. PDF.
Borrow, Nik, et Ron Demey. 2013. Field Guide to the Birds of Ghana. Bloomsbury Publishing. ISBN 9781408189023.
Campbell, Bruce, et Elizabeth Lack. 2010. A Dictionary of Birds. Londinii: A. & C. Black. ISBN 9781408138380.
Carnaby, Trevor. 2008. Beat about the bush: Birds. Iohannesburgi: Jacana. ISBN 9781770092419.
Cuevas Martínez, Rafael, et Enrique Gómez Merino. 2011. Jilgueros y especies afines. Editorial Hispano Europea. ISBN 9788425517273.
Dutson, Guy, et Richard Allen. 2011. Birds of Melanesia the Bismarcks, Solomons, Vanuatu and New Caledonia. Londinii: Christopher Helm. ISBN 9781408152461.
Vinicombe, Keith, et Alan Harris, et Laurel Tucker. 2014. The Helm guide to bird identification: an in-depth look at confusion species. Londinii: Christopher Helm. ISBN 9781408130353.
Zimmerman, Dale A., et al. 1999. Birds of Kenya and Northern Tanzania. Princetoniae: Princeton University Press. ISBN 0691010226.

Anatomia avium