How to Fix an Eye
Basic background information
- Seeing the Cells That See
Ever since the eye's rods and cones were discovered, scientists have been trying to observe them in action. But the retinal photoreceptors, which change light into electrical pulses the brain can process, are so tiny and their flashes of activity so brief that they have eluded researchers.
Finally, last fall, a team led by David R. Williams of the University of Rochester managed to peek at and photograph human cones. As demonstrated in this picture, researchers used a laser to illuminate the retina; a high-resolution camera borrowed from astronomers recorded the image. The cones, shown here in the black-and-white inset, are three microns wide and are responsible for color and daytime vision.
Marguerite Holloway, Scientific American, January 1995. Volume 272, Number 1, Page 27.
Excellent textbook treatment of the anatomy and physiology of invertebrate and vertebrate function.
N. A. Campbell. In Biology. 2nd Edition. by Neil A. Campbell. Pages 1016 - 1023.
- How Photoreceptor Cells Respond To Light
New information about how light energy is changed into neural signals shows how an individual photoreceptor cell of the eye registers the absorption of a single photon, or quantum of light. Subjects: cone cells, nerve impulse, retina, rod cells, vision, visual pigments.
Julie L. Schnapf, Denis A. Baylor. Scientific American. April, 1987. Page 40 US, page 32 Intl.
- The Functional Architecture Of The Retina
Dozens of kinds of cells have specialized roles in encoding the visual world. New techniques have made it possible to study the arrangement and interconnections of entire populations of cells. Subjects: amacrine cells, nerve circuits, receptive field, retina, vision.
Richard H. Masland. Scientific American. December, 1986. Page 102 US, page 90 Intl.
- The Molecules Of Visual Excitation
When a rod cell in the retina absorbs light, a cascade of reactions results in a nerve signal. That cascade has now been worked out in molecular detail. A key intermediate is a protein called transducin. Subjects: cyclic GMP, hormones, nerve impulse, rhodopsin, rod cells, transducin, vision, visual pigments.
Lubert Stryer. Scientific American. July, 1987. Page 42 US, page 32 Intl.
Some interesting WWW sites related to vision
- A Chronological History of Vision Research: 1600-1960
There are many well known accounts of the history of visual science but it seems hard to find a simple chronological listing of major events. Sometimes such a list can be helpful in gaining a quick historical perspective. This note presents a chronology listing 133 significant events between 1600 and 1960. In addition, for completeness sake, there is a brief preliminary section that sketches the history of visual science before 1600. All of this material is based on standard secondary sources: the author (Jack Yellott) is not a specialist in the history of science, and the object here is not to contribute anything new to the history of vision research but rather simply to collate material already scattered throughout the literature--though of course the choice of "significant" events is idiosyncratic.
- B-EYE: The world through the eyes of a bee
Does the world look the same to everyone and everything? Check out B-EYE to see how HONEY BEES see the world. A fun and interesting Web site!
- Vision Science: the World-wide Web Virtual Library
This is a collection of links to sites concerned with research in the vision of humans and of other organisms.
Science Seminars Archive