Non-Visual Photoreception: Sensing Light without Sight

Department of Ophthalmology, University of Washington Medical School, Seattle, Washington, USA.
Current Biology (Impact Factor: 9.57). 02/2008; 18(1):R38-9. DOI: 10.1016/j.cub.2007.11.027
Source: PubMed

ABSTRACT Recent work in blind human subjects has confirmed the presence of a non-visual ocular photoreceptive mechanism similar to that described in blind mice. This system appears to subserve circadian photic entrainment, the pupillary light response, and a number of other aspects of neurophysiology and behavior.

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    Philosophical Transactions of The Royal Society B Biological Sciences 11/2009; 364(1531):2833-47. DOI:10.1098/rstb.2009.0083 · 7.06 Impact Factor
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    • "Though they are located within the retina, these cells do not function in image formation; instead, they appear to serve a circadian function. It is for this reason that some blind people lacking rods and cones can nonetheless respond to day–night cycles (Van Gelder 2007; Zaidi et al. 2007). The cases of Platynereis, Tripedalia, and humans suggest that most animals will turn out to exhibit both types of photoreceptor cells, or at least that they had both at some stage in their ancestry (Plachetzki et al. 2005). "
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