What It’s Like To Go Blind

This is important for scientists and non-scientists alike.  You might be surprised at how many people do not know someone who is blind or has gone through a blinding disease.  You might be further surprised at how many scientists that are engaged in vision research do not really know what its like to have gone through vision loss or have similarly interacted with someone who is going blind.  As I’ve said before in The Judgment Of Solomon post, “Every scientist studying vision and diseases affecting vision should have the opportunity to spend time with those who have lost sight.  It is important for people in the sciences to sit down and talk with those affected by the disease they study.”

The subject of this short, Mark has a cone/rod dystrophy due to a defect in the ABCA4 gene, which codes for an ATP-binding cassette transporter family.  Kris Palczewski’s group has shown that these defects ultimately cause a buildup of all trans retinal in the outer segments of the photoreceptors and leads to likely oxidative damage, cell stress and photoreceptor toxicity.  This photoreceptor toxicity then ultimately results in photoreceptor cell death and blindness.

 

Portrait of Vision Scientist: Jun Yang

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Jun Yang‘s lab focuses on the molecular mechanisms of hereditary retinal degenerative diseases, focusing specifically on the mechanisms of a set of inherited diseases in Usher Syndrome where people go blind and deaf due to defects in the cytoskeleton of photoreceptors in the eye and hair cells in the ear.  She explores the cell biology of photoreceptors with mouse models of Usher Syndrome and a combination of approaches in molecular and cellular biology, biochemistry, electrophysiology, behavior and microscopy. Continue reading “Portrait of Vision Scientist: Jun Yang”

Glowing Sharks Have Unusual Eyes

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There are species of shark that are bioluminescent and have evolved ocular structures designed to detect faint light patterns in the deep ocean produced by other bioluminescent sharks that live at depths from 600 to 3,000 feet in the mesopelagic zone where very little sunlight reaches.

These eyes as expected, have visual adaptations optimized for this environment.  Julien Claes, the lead authors of a new study notes that “There are about 50 different shark species that are able to produce light”.  Given that there are 50 separate bioluminescent species of shark, one might expect some visual system specializations and indeed there are.  Everything from higher rod densities to descriptions of bioluminescent specializations used for communication and specialized transparencies in the upper socket of the eye to help adjust illumination. Continue reading “Glowing Sharks Have Unusual Eyes”