Portrait Of Vision Scientist: Ann Morris

Ann-Morris

Ann Morris from the University of Kentucky studies the zebrafish (Danio rerio).  In particular, she studies the ability of zebrafish retinas to regenerate following retinal injury or damage.  Retinal regeneration is an interesting phenomenon that mammalians seem to lack and yet zebrafish manage to do this despite having a retina that in many ways is far more complex than the mammalian retina.

Ann talks about her work in the following video from the University of Kentucky: Continue reading “Portrait Of Vision Scientist: Ann Morris”

Evolution of Sight in the Animal Kingdom

This amazing video produced by the History Channel, Vision and Evolution of the Eye is well worth 40 minutes of your time.  The evolution of visual systems is something that we here at Webvision are very interested in.  Also note that we have an excellent chapter on the Evolution of Phototransduction, Vertebrate Photoreceptors and Retina by Trevor Lamb here on Webvision.

 

This accompanying text below on this post was sent to us by friend of Webvision, Dr. Dominic Man-Kit Lam.  Dr. Lam was born in Swatow, and grew up in Hong Kong. He studied under two Nobel Laureates at Harvard Medical School before joining the Harvard Faculty and subsequently became Professor of Ophthalmology and Chairman of Center for Biotechnology at Baylor College of Medicine in Houston. He is the president of the World Eye Organisation, A charitable organization dedicated to the prevention and treatment of eye disorders for the poor.  Continue reading “Evolution of Sight in the Animal Kingdom”

Blind Kenyan Runner Has Far-Reaching Vision

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NPR has a wonderful story of childhood friends, Henry Wanyoike and Joseph Kibunja who started running together as children 30 years ago and are still running in competition today.  That is a remarkable story enough, but even more compelling is that Wanyoike is blind from a stroke that cost him his sight and Kibunja is his running guide.

It is a wonderful story and well worth the read.  While there, also be sure to stop by the Henry Wanyoike Foundation website, designed to help bring young people together through sport.

 

 

 

Moving Jumping Spider Retinas

We’ve talked about jumping spiders before here on Webvision as they are an amazing animal with very well developed vision.  However, their retinas and visual pathways are very different from the vertebrate retinas in that they use image defocusing for depth perception rather than parallax like humans and other vertebrates do.  Figuring out spider vision has been a long standing effort by a small group of scientists and one of the problems of observing spiders is figuring out how they scan.  The movie above however shows a transparent jumping spider with the pigment cells in its eyes/retinas moving while they scan an image.  There is another pretty impressive movie here, showing a microscopic view into the retina of a living jumping spider.

Hat tip to Sung Soo Kim who found this and retweeted Richard Dawkins on Twitter.

 

Benham’s Top Illusion

Benhams Top

Benham’s Top or Benham’s disk is named after Charles Benham, a toy maker but also an amateur scientist who contributed and published articles to the likes of Nature.  Benham’s observation with a toy top was relayed through an article in Nature in 1894 that described a visual phenomenon generated by a toy top painted like the above image.  When spun, the Fechner color effect is perceived.  Not everyone perceives the same colors…

 

Continue reading “Benham’s Top Illusion”