…the cornea is transparent, so when viewed from the outside, the iris behind it is visible, and the pupil is in the center. The cornea becomes opaque at the periphery and continues to the sclera (the transition to the sclera is called the limbus). The curvature of the sclera is less steep than that of the cornea, so if the eyeball is cut into a circular slice, the cornea protrudes into a part of the larger circle of the sclera. … From [Sclera]…the eyeball can rotate smoothly in all directions with the aid of the six extraocular muscles attached via their tendons. Behind the sclera, the optic nerve and central retinal artery and vein pass through the lamina cribrosa, which is made up of the inner sclera. The short ciliary arteries to the choroid pass around the optic nerve, while the long ciliary arteries pass through the sclera anteriorly near the limbus (where the sclera merges into the cornea). Veins from the uvea (vortex veins) also pass through the sclera near the equator. … *Some of the terminology that refers to the "corneal limbus" is listed below. Source | Heibonsha World Encyclopedia 2nd Edition | Information |
…角膜は透明であるため,外から見るとその奥にある虹彩irisが見え,中央が瞳孔となっている。角膜は周辺部では不透明となり強膜に続く(強膜への移行部を角膜輪部という)。強膜の曲率は角膜よりゆるく,眼球を輪切りにすれば,強膜の大きな円の一部に角膜が突出した形となる。… 【強膜】より…このため,腱を介して付着する6本の外眼筋の作用によって,眼球は滑らかに各方向に回転することができる。強膜の後方では,視神経と網膜中心動静脈が,内側強膜からなる篩状板lamina cribrosaを貫き,脈絡膜への短毛様動脈が視神経の周囲で,また前方では,長毛様動脈が角膜輪部(強膜が角膜へ移行する部分)近くで強膜を貫く。ぶどう膜からの静脈(渦静脈)も赤道部付近を貫く。… ※「角膜輪部」について言及している用語解説の一部を掲載しています。 出典|株式会社平凡社世界大百科事典 第2版について | 情報 |
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