File:Dragonfly eye 3811.jpg

已授权您依据自由软件基金会发行的无固定段落及封面封底文字（Invariant Sections, Front-Cover Texts, and Back-Cover Texts）的GNU自由文件许可协议1.2版或任意后续版本的条款，复制、传播和／或修改本文件。该协议的副本请见“GNU Free Documentation License”。http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue

	本文件采用知识共享署名-相同方式共享 3.0 未本地化版本许可协议授权。
	您可以自由地： 共享 – 复制、发行并传播本作品 修改 – 改编作品 惟须遵守下列条件： 署名 – 您必须对作品进行署名，提供授权条款的链接，并说明是否对原始内容进行了更改。您可以用任何合理的方式来署名，但不得以任何方式表明许可人认可您或您的使用。 相同方式共享 – 如果您再混合、转换或者基于本作品进行创作，您必须以与原先许可协议相同或相兼容的许可协议分发您贡献的作品。
	本许可协议标签作为GFDL许可协议更新的组成部分被添加至本文件。http://creativecommons.org/licenses/by-sa/3.0/CC BY-SA 3.0Creative Commons Attribution-Share Alike 3.0truetrue

Dragonfly with compound eyes. Author: David L. Green

A compound eye is a visual organ found in certain arthropods. The compound eye consists of between 12 and 1,000 ommatidia, little dark/bright sensors. The image perceived by the arthropod is "recalculated" from the numerous ommatidia which point in slightly different directions. In contrast to other eye types, there is no central lens or retina. Though the resulting image is poor in resolution, it can detect quick movements and, in some cases, the polarization of light. Dragonflies have about 30,000 facets to their compound eyes, giving them nearly a 360° field of vision. Photo credit: David L. Green

m:Image:Dragonfly eye 3811.jpg