34

TL;DR: The claim is actually false. Cats and Dogs (as well as many other animals) just see the world differently from humans. We would call them colourblind, but not greyscale colorblind. I run into this claim A LOT, so I feel that it is indeed a great skeptical claim. At the very least a teaching moment to introduce what skepticism means since this is ...


28

Snopes lists it as unproven. http://m.snopes.com/camera-flash-blind-baby/ The Daily Mail pointed to the unreliable People’s Daily Online as the source of this information, who in turn sourced their story from Guangming Daily, who sourced their reporting from QQ.com, who cited DAHE.com, who got their information from Henan TV. At no point in this ...


22

I don't think this is correct. Your eye muscles might get 'tired' but there's no reason for damage to the eye to occur in terms of vision. Our eyes have evolved to compensate for motion very well. There is a similar myth that reading in low light damages the eye. You're more likely to have a problem with car sickness. This is thought to be caused by a ...


16

The "damage" done by screens is in the form of eye strain. Your eyeball focuses by using muscles in the eye to change the shape of the lens within the eye, to properly focus incoming light onto the correct portion of the retina. It is the second part of your eye, after the cornea, that helps to focus light and images on your retina. Because the lens is ...


11

The claim at Quora is close to the mark, although not exactly for the reason claimed. All lenses (including our eyes) suffer from chromatic aberration, a kind of distortion that occurs because different colors have different refractive indexes. In photographs, this distortion results in fringes of color in high-contrast areas. In eyesight, it can increase ...


11

What you described sounds like the Absolute Threshold in neuroscience. It is commonly defined as "The lowest amount of stimulus that a person can detect 50 percent of the time." According to an experimental research conducted by Hecht, Shlaer, and Pirenne (1942), the smallest number of photons that could elicit a visual experience is 90 photons, while ...


10

Yes, it is recognised as a potential problem: LED lighting flicker and potential health concerns: IEEE standard PAR1789 update. The IEEE Standards Working Group, IEEE PAR1789 “Recommending practices for modulating current in High Brightness LEDs for mitigating health risks to viewers” has been formed to advise the lighting industry, ANSI/NEMA, IEC, ...


8

This should really be a comment, as I have only partial information and am neither able to conclusively strengthen or refute the claim, however I can throw some information into the debate. I'll start with the part of the claim that "specifies" what happens: eventually needs glasses Besides the (trivial) fact that almost everyone eventually needs ...


8

Low contrast modes that rely on colour are not a boon, despite the design trends. Complementary colour contrasts may be perceived as strenuous but overall eye fatigue is reduced and readability improved if the contrast is high! Themes like "solarized" are quite terrible in most situations. It was believed that because screen reflections are imaged behind ...


7

No, watching too much television does not directly cause myopia. Walter Wood has debunked the theory that too much near work causes myopia. In his book The Ultimate Unification of Diet Health and Disease he makes the following points/observations: In a study published in January 2011 80 7-11-year olds were randomly assigned into intervention or ...


7

They may be beneficial from the American Optometric Association: Eyeglasses or contact lenses prescribed for general use may not be adequate for computer work. Lenses prescribed to meet the unique visual demands of computer viewing may be needed. Special lens designs, lens powers or lens tints or coatings may help to maximize visual abilities and comfort. ...


7

Assuming you are talking about what is commonly know as "lazy eye" or amblyopia from a medical standpoint, then yes patching the dominate eye is a common treatment that is used (see also, 1, 2, 3, 4). However, other treatments such as eye drops may be used to force the weaker eye to get stronger by blurring the vision in the dominate eye. When should ...


6

There are more problems which can occur from "staring" on screen. Eye discomfort Headaches Itchy eyes Dry or watering eyes Burning sensations Changes in color perception Blurred vision Difficulty focussing (1, 2, 3) Ways to minimise damage to your eyes caused by computer screens There are several ways you can minimise the potential damage to your eyes ...


6

Retina Display is unhealthy, but it's unrelated to the resolution. It's the fact, that it's offered only as glossy display, no matte option. Queensland University of Technology page on "High gloss computer screens" This web page contains health and safety considerations for Macintosh – Apple ‘glass’ or high gloss monitor screens. Reflections and ...


6

A new perspective on spontaneous blinks Ophthalmology 2013 May; 120(5):1086-91 Blink rate was significantly higher in women than in men (P = 0.007, unpaired t test; female, 22.0 ± 16.8 blinks/minute; male, 8.6 ± 7.2 blinks/minute). See also Analysis of blink rate patterns in normal subjects Movement Disorders 1997 Nov;12(6):1028-34. Women had a ...


5

The title of the question asks if most blindness solved by cadaver donation? The World Health Organization states that: According to the latest assessment, cataract is responsible for 51% of world blindness [1] So, cataracts are responsible for the majority of blindness. Cataracts are readily treated by replacement of the lens of the eye with an ...


5

Personal computers are possibly one of the most empowering tool humanity has ever created. They're tools of communication, creativity, and they can be shaped by the user. But, of course they "computers" come with various negative effects. One negative effect is affecting your eyesight. Computer users (including me) have reported many eyesight problems like ...


5

This page, which includes relevant calculations, suggests a limit closer to 10km. The calculations compare seeing a candle to seeing a 6th magnitude star. There's additional discussion assuming an ability to see 7th and 8th magnitude stars, but 6th is generally considered the naked eye limit. Even 10km strikes me as ambitious, since it does not take into ...


5

Referring to Martin Gardner in the book 'Fads and Fallacies in the Name of Science' Chapter 19 'Throw Away Your Glasses', there had been no changes in the cornea opacity of Aldous Huxley to indicate better or improvement in vision due to the alternative Bate's method therapy. The following quotation is from Bennett Cerf's column in The Saturday Review, ...


5

Summary: complete colour blindness is very rare (less than 0.01%). What's common is deficiency in red-green colour vision in men, which is around 8% (sex-linked because it's from an X-chromosome fault). This is based on a huge amount of evidence from accurate, widespread diagnostic testing. You're unlikely to notice it in another person through normal ...


5

Personal test experiment, (more of an extended comment than an answer)... Sometimes I have to drive a four door sedan at night, during times of sporadic traffic, in a town with curvy roads and hills where about half the cars on the road are SUVs, and half of those never seem to turn off their hi-beams. On a straight road the oncoming hi-beams needn't be so ...


5

There is some fairly old research suggesting that night-driving glasses, i.e. glasses with tinted glass, do not make it easier to see at night, and might even have a detrimental effect. Both acuity and contrast appear to be impaired (note: with the exception of the first paper by Lauer et al. 1949, I'm going by the online summaries, as I currently don't have ...


5

If any study has looked directly at this question, it should not be too hard to find, but I also am not finding it. The only direct expression of professional opinion on this I've found so far is in this article. It states that "retinal detachment was judged to be unrelated to lens wear" by three of the authors. This seems to be based on general clinical ...


4

Referring to FTC, the California-based marketers Carrot Neurotechnology, Inc. and its co-owners have agreed to stop making deceptive claims that their software application '“Ultimeyes” for mobile devices and personal computers can improve users’ vision in order to settle FTC charges under the terms of a proposed settlement of $150,000. Quoting Jessica ...


4

"Permanent damage to the retina has been shown to occur in ~100 seconds" Source: http://scienceline.ucsb.edu/getkey.php?key=3269 A similar statement: "sungazing at bright midnoon for 100 s can produce a threshold lesion." Source: W. T. Ham, Jr., H. A Mueller, and D. H. Sliney Retinal sensitivity to damage from short wavelength light Nature 260, 153-155 (...


3

No exactly like that, but the lack of outdoor/intense light exposure is an environmental risk factor in developing myopia. This factor is directly correlated with education, at least as currently practiced in East Asia, so a gene x environment interaction is probably the best description. The mechanism how lack of exposure to intense light causes myopia is ...


3

There was work done after WWII on this issue. Millard and McCann fed high levels of vitamin A2 to eight medical students at the University of Rochester School of Medicine; the control group of seven medical students did not receive vitamin A2. Students in the experimental group had a 30% lowering of the threshold for red light, a 25% improvement of red in ...


2

Color theorists suspect that many color associations emerge from evolutionary ingrained responses to color stimuli (Mollon, 1989 http://jeb.biologists.org/content/146/1/21.full.pdf). Research indicates that colors often serve a signal function for nonhuman animals (e.g., the redness of fruit signals readiness for eating), thereby facilitating fitness-...


2

Critical flicker frequency (the rate at which you can no longer distinguish a flickering light from a constant one) isn't everything. Research during World War II and afterwards using a tachistoscope demonstrated that people can identify airplanes or make correct shoot/don't shoot decisions based on images seen for as little as 1/100 of a second.


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