Send to

Choose Destination
Curr Biol. 2009 Jan 27;19(2):108-14. doi: 10.1016/j.cub.2008.11.061. Epub 2008 Dec 24.

A novel vertebrate eye using both refractive and reflective optics.

Author information

Anatomisches Institut, Universität Tübingen, Osterbergstrasse 3, 72074 Tübingen, Germany.


Sunlight is attenuated rapidly in the ocean, resulting in little visually useful light reaching deeper than approximately 1000 m in even the clearest water. To maximize sensitivity to the relatively brighter downwelling sunlight, to view the silhouette of animals above them, and to increase the binocular overlap of their eyes, many mesopelagic animals have developed upward-pointing tubular eyes. However, these sacrifice the ability to detect bioluminescent and reflective objects in other directions. Thus, some mesopelagic fish with tubular eyes extend their visual fields laterally and/or ventrally by lensless ocular diverticula, which are thought to provide unfocused images, allowing only simple detection of objects, with little spatial resolution. Here, we show that a medial mirror within the ventrally facing ocular diverticulum of the spookfish, Dolichopteryx longipes, consisting of a multilayer stack derived from a retinal tapetum, is used to reflect light onto a lateral retina. The reflective plates are not orientated parallel to the surface of the mirror. Instead, plate angles change progressively around the mirror, and computer modeling indicates that this provides a well-focused image. This is the first report of an ocular image being formed in a vertebrate eye by a mirror.

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center