Archive for March, 2012

Aging Eyes Blamed For Seniors’ Health Woes

Friday, March 9th, 2012

Source: Slashdot


Title Aging Eyes Blamed For Seniors’ Health Woes


Dr. Martin Mainster has written extensively about the effects of the aging eye on health, estimate that by age 45, the photoreceptors of the average adult receive just 50 percent of the light needed to fully stimulate the circadian system, by age 55, it dips to 37 percent, and by age 75, to a mere 17 percent and recommend that people should make an effort to expose themselves to bright sunlight or bright indoor lighting when they cannot get outdoors and have installed skylights and extra fluorescent lights in their own offices to help offset the aging of their own eyes.

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Comments: Many of us do not realise that our requirements for light change as we get older. For those planning the lighting for a house for the elderly, they would do well to pay attention to the statistics given above and ensure that sufficient light is available.



Hotel horror: Mirror, mirror, who’s that in my bathroom?

Monday, March 5th, 2012

Source: Detroit Free Press


Title Hotel horror: Mirror, mirror, who’s that in my bathroom?


Gray skin, haggard wrinkles and bags under the eyes. It’s like watching a horror movie, except it’s me. What kind of sadist puts overhead fluorescent lights in a hotel bathroom to terrify the guests?


At least install lights on both sides of the sink, not above. Use regular incandescent lights, or halogen lights, or indirect lights, or LED lights, or at least those full-spectrum, natural daylight fluorescents instead of those glaring, hideous old-fashioned models.


Hotel managers, I will tell you why you must invest in this. A hotel guest who thinks he or she looks good is a happy guest. Happy guests complain less. Happy guests leave better tips. Happy guests will probably come back.

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Comments: This author is observant enough to notice the difference in light quality in the hotels she has stayed. Her point – don’t make clients suffer through cheap inferior lighting, they’ll be happier if they have full-spectrum light available. Next time you stay in a hotel – take a note and see what you notice.



Jumping Spiders Use Image Defocusing For Depth Perception

Thursday, March 1st, 2012

Source: Webvision


Title Jumping Spiders Use Image Defocusing For Depth Perception


The experiment was one of those experiments that is elegant in its simplicity. When using just green light to illuminate prey, the spiders were always accurate in their strikes, just light in full spectrum light. However, when green light was excluded and red light exclusively was used to illuminate prey, the spiders attacks on prey were typically short.

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Comments: While nominally about how spiders hunt, we were interested in this article for the information contained on how the eyes of one particular species have evolved to take advantage of different spectrum within the light we see and how they are disadvantaged when even one colour is removed from their available light spectrum. And to think we see all those options as simply white.