位於牆上或穹頂冠上的圓形或橢圓形小開孔。若以眼睛形狀作為設計之主題，則稱之為「眼狀物(紋飾)」。

牛眼窗(開口)　(P,,U,繁體中文-偏好,D,U,U)
小圓窗(開口組件)　(,U,繁體中文-非偏好,UF,U,U)
圓窗(,U,繁體中文-非偏好,UF,U,U)
眼狀孔(,U,繁體中文-非偏好,UF,U,U)
niu yan ch'uang (P,,U,韋氏拼音-偏好,UF,,)
niú yǎn chuāng (P,,U,漢語拼音-偏好,UF,,)
niu yan chuang (P,,U,漢語拼音(無聲調)-偏好,UF,,)
oculi(openings)　(P,,U,英文-偏好,D,U,PN)
oculi(P,,U,荷蘭語-非偏好,D,U,U)
oculus(opening)　(,U,英文-非偏好,AD,U,SN)
oculus(,U,荷蘭語-非偏好,AD,U,U)
bull's-eyes(,U,英文-非偏好,UF,U,N)
bull's eye windows(,U,英文-非偏好,UF,U,N)
bull's-eye windows(,U,英文-非偏好,UF,U,N)
roundels(windows)　(,U,英文-非偏好,UF,U,N)
windows, bull's eye(,U,英文-非偏好,UF,U,N)
windows, bull's-eye(,U,英文-非偏好,UF,U,N)
óculos(P,,U,西班牙語-偏好,D,U,PN)
óculo(,U,西班牙語-非偏好,AD,U,SN)

藝術與建築詞典根目錄
....物件層面
........組件 (層級名)
............成分
................<依特定背景區分之組件>
....................建築元素
........................<開口與開口結構>
............................開口
................................<依形式區分之開口>
....................................牛眼窗 (開口)

distinguished from....

眼狀物(紋飾)

英文....	Small round or oval openings, such as windows in a wall or openings in the crown of a dome. For the design motif in the shape of an eye, use "eyes."
荷蘭語....	Wordt gebruikt voor kleine ronde of ovale openingen, zoals ramen in een muur of openingen in de top van een koepel.

牛眼窗(開口)............	[AS-Academia Sinica]
.................	台灣古建築圖解事典 199
.................	建築學英漢辭典 61
.................	大英百科全書線上繁體中文版 October 3, 2012
小圓窗(開口組件)............	[AS-Academia Sinica]
.................	世界建築經典圖鑑 332
圓窗............	[AS-Academia Sinica]
.................	大英百科全書線上繁體中文版 October 3, 2012
.................	劍橋藝術史－中世紀 130
眼狀孔............	[AS-Academia Sinica]
.................	大英視覺藝術百科全書 Vol. 9, 186
oculi(openings)............	[VP]
.................	Lever and Harris, Illustrated Glossary of Architecture (1966) illustration; oculi
.................	Sturgis, Dictionary of Architecture and Building (1902) oculi
.................	Webster's Third New International Dictionary (1961) oculi
.................	Avery Index (1963-) (source AAT); oculi
.................	BHA Subject Headings (1985-) oculi
.................	AAT-Ned (1994-)
oculus(opening)............	[VP]
.................	Getty Vocabulary Program rules oculus
.................	AAT-Ned (1994-)
bull's-eyes............	[VP]
.................	Dictionary of Architecture and Construction (1975) illustration
.................	Random House Dictionary of the English Language (1987)
bull's eye windows............	[VP]
.................	Lever and Harris, Illustrated Glossary of Architecture (1966) illustration
.................	Encyclopaedia Britannica (1973)
bull's-eye windows............	[VP]
.................	Random House Dictionary of the English Language (1987)
roundels(windows)............	[VP]
.................	Dictionary of Architecture and Construction (1975) roundels
.................	Getty Vocabulary Program rules
.................	Kostof, Castillo, and Tobias, History of Architecture (1995) GLOS; roundels
windows, bull's eye............	[VP]
.................	Getty Vocabulary Program rules
windows, bull's-eye............	[VP]
.................	Getty Vocabulary Program rules
óculos............	[VP]
.................	TAA database (2000-)
óculo............	[VP]
.................	Paniagua, Vocabulario Básico de Arquitectura (1998) 232
.................	Toman, El Barroco. Arquitectura, escultura, pintura (1997) 485

Getty AAT: 300069431 Getty AAT: http://www.getty.edu/vow/AATFullDisplay?find=costume&logic=AND¬e=&subjectid=300069431
聯合目錄： 牛眼窗 、小圓窗 、圓窗 、眼狀孔 、niu yan ch'uang 、niú yǎn chuāng 、niu yan chuang 、oculi 、oculus 、bull's-eyes 、bull's eye windows 、bull's-eye windows 、roundels 、windows, bull's eye 、windows, bull's-eye 、oculi 、oculus 、óculos 、óculo