Related Experiment Video
Updated: Jun 26, 2026
09:20
Novel Photoacoustic Microscopy and Optical Coherence Tomography Dual-modality Chorioretinal Imaging in Living Rabbit Eyes
Published on: February 8, 2018
A novel vertebrate eye using both refractive and reflective optics.
Hans-Joachim Wagner1, Ron H Douglas, Tamara M Frank
1Anatomisches Institut, Universität Tübingen, Osterbergstrasse 3, 72074 Tübingen, Germany.
Current Biology : CB
|December 27, 2008
Summary
Spookfish use a unique mirror in their eyes to see in the dark deep ocean. This mirror, made from retinal tissue, creates a focused image, a first for vertebrate eyes.
Area of Science:
- Marine biology
- Comparative anatomy
- Vision science
Background:
- Sunlight rapidly attenuates in the ocean, limiting vision in mesopelagic zones.
- Mesopelagic animals often have tubular eyes for detecting silhouettes but sacrifice peripheral vision.
- Lensless ocular diverticula in some fish are thought to provide unfocused images for object detection.
Purpose of the Study:
- To investigate the function of ocular diverticula in mesopelagic fish.
- To determine how the spookfish (Dolichopteryx longipes) achieves extended visual fields.
- To identify the mechanism behind image formation in the spookfish's ventral ocular diverticulum.
Main Methods:
- Microscopic examination of the spookfish's ocular diverticulum.
- Analysis of the reflective structures within the diverticulum.
- Computer modeling to simulate image formation.
Main Results:
- A medial mirror, derived from a retinal tapetum, was identified in the ventral ocular diverticulum.
- The mirror's reflective plates are not parallel but have progressive angle changes.
- Computer modeling demonstrated that these angled plates form a well-focused image.
Conclusions:
- The spookfish utilizes a novel mirror system for image formation in its ocular diverticulum.
- This represents the first documented instance of a vertebrate eye forming an ocular image using a mirror.
- The specialized eye structure enhances visual capabilities in the low-light mesopelagic environment.
Related Concept Videos
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
01:17Accessory Structures of the Eye
Optical perception, or vision, is an extraordinary sense dependent on converting light signals received via the ocular organs. These organs, known as eyes, are securely positioned within the bony cavities of the skull, called orbits. The orbits serve a dual purpose: a protective shield for the ocular globes and a stable attachment point for the soft ocular tissues. The eye's external protective mechanisms include the eyelids, which are edged with lashes that act as a barrier against foreign...
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...