Our Response to a Neuroscientist’s Rebuttal

A rather interesting rebuttal to our current project was recently printed on Petapixel.


Our response to this rebuttal is as follows:

First of all, I completely agree with you in regards to the infrared spectrum as most people think of it as being out of the reach of vision in general. We have been quite careful to distinguish that our project is seeking a visual response in the near infrared spectrum which has been demonstrated time and time again in a number of different ways. While I wasn’t working with those exact values for absorption, I am familiar with cone and rod absorption curves. The Rhodopsin curve tapers off near 700nm assuming a certain level of light intensity. The ISO 20473 scheme defines near infrared as beginning at 780nm. Because of the slow taper at the high end of the rhodopsin absorption curve even rhodopsin is sensitive to a 780nm wavelength of light given a high enough magnitude. I believe I know where you got this “absolute limit of long wavelength photoreceptors” being 650nm but I’ve never seen this number in a journal. It matches none of the research or data that I’ve seen and trust me.. I’ve seen quite a lot. First, I’d like to argue against this 650nm limit you describe. As far back as 1955, Brindley discussed the “yellowing” of light that occurs when wavelengths longer than 700nm and of sufficient magnitude are subjectively described. For example, subjects described an 850nm light of sufficient brightness as being orange rather than red. Of course, this study was subjective but electrophysiology studies have since confirmed this. T.D. Lamb’s article in Vision Research Volume 35, Issue 22 proposes an equation attempting to match these findings. Your claim of an “absolute limit of long wavelength light” without once mentioning lumens is an erroneous statement. If you’d like, I can certainly provide you with links to a few good textbooks regarding photometry that can help you understand what I’m talking about. Now, I am perfectly willing to acknowledge that I may be misinterpreting some of the data and fine points of these journal articles. I do not have a PhD in your field; however, I take issue with some of the values you presented.

You state:

In short, there are 4 kinds of photoreceptors in our eyes, rod photoreceptors which detect electromagnetic spectral energy from ~400nm to ~580nm with maximal sensitivity at 496nm (blue/green light)

The long wavelength sensitive, L-cones (“red cones”) are known to be maximally sensitive to wavelengths peaking around ~560nm, medium wavelength sensitive, M-cones (“green cones”) peak around ~530nm and short wavelength cones, S-cones (“blue cones”) peak at ~420nm respectively.


I found it strange that you chose these values which are rather outdated. I have the Bowmaker and Dartnell article which dates back to 1980 proposing these values. The 2004 Hunt (Didn’t you coauthor a work with Hunt?) work is far more recent and likely its sources more accurate. You also chose 496nm as the Rhodopsin maximum sensitivity. The most commonly reported value is 498nm. While trying to backtrack your data… I found your source. Your single and sorely misinterpreted source was Helga Kolb’s Webvision page from which you word for word took the majority of your explanation. The worst aspect of all is that you interpret image figure 14a as somehow indicative of a 650nm cutoff that you’re promoting as an “absolute limit of long wavelength photoreceptors.” This type of occurrence is exactly why independent researchers are so vital to the advancement of science. I’m sure some people will believe your criticisms based on the fallacy of appeal to authority regardless of your blatant plagiarism from a single source.


The bottom line here is that even without dehydroretinal which contemporary studies have shown to peak closer to 620nm rather than the 522nm or so reported by Wald, humans can already see into the near infrared spectrum assuming a light of appropriate intensity. By replacing the retinol in the human eye with dehydroretinol it’s very likely that the observable spectra will shift further into the NIR range and become observable at a lower intensity such as normally present around us at all times. I say this is likely as it has been demonstrated time and time again in murine models with electrophysiological measures which if you’d taken the time to read, is described and cited in detail in our original study proposals. I agree with you that we have a serious problem with ignorance towards science in this country but I’d like to add that quote mining a source without so much as fully understanding the material isn’t any better than blind faith.


Furthermore, I can’t emphasize how much you’ve jumped to conclusions without taking any time to read our protocols. Sure, the images posted state “850nm Flashes” and “950nm Flashes.” This is referring to the wavelength of peak light emission of the LED, not some pure wavelength of light. Had you read any of our design posts, you’d have seen the section explaining why our control light which is clearly visible by any person with normal and unaugmented vision is labeled 850nm. An 850nm LED bleeds a swath of light with wavelengths in the normal range of human vision. We have all of the documentation detailing the curve of different wavelengths being emitted by the 950 and higher wavelength LEDs as well. Of course, you didn’t take the time to read anything we’ve written or worked on and instead pasted together a rather remedial introduction to the physiology of the eye. Yes, I am aware of the work you’ve done and the articles you’ve written. I have no doubt that your understanding of the eye is far greater than mine; however, you haven’t taken the time to actually read what we’re doing. Your rebuttal is little more than a leap to a conclusion heavily seasoned with condescension.











7 thoughts on “Our Response to a Neuroscientist’s Rebuttal”

  1. It is important to understand that many of these studies including the modern ones you cite on the spectral properties of various opsins were performed in spectrophotometer cuvettes. Not in intact organisms for good reasons. You can get any molecule to excite and induce resonance and extend its absorption/emissions curves. The problem is that beyond some ranges, it is not biological and it causes damage. In the UV spectrum, those energies cause vibrational energy to chemical bonds and break them. In the IR range, you cook proteins.

    So, after 1947 when optics and light energy started becoming more of an interest (lasers, etc…), it was found that IR and near IR radiation is dangerous to ocular tissues. Most of the studies performed have been looking at mid and far IR, but its been found that the cornea absorbs most of the wavelengths above and beyond 1400nm to around 3000nm. The real problem with the IR-A or near infrared is the lens which absorbs IR energy from around 900nm to 1400nm. When this happens, you get cataracts. Bad ones. This has been known since at least the 1700s when people started using telescopes to look at the sun or when glassblowers in Italy started developing cataracts. I think there is some industrial health literature that covers some of this, but its been years since I read it deep in the stacks of the library someplace.

    Below around 1400nm, that energy is absorbed by the retina. That means heating of the retina and heating of structures that are already operating on the edge of oxidative damage. The interface between the photoreceptors and the retinal pigment epithelium is the area of your body with the highest oxygen turn over per unit volume and its running on the ragged edge of its ability to detoxify and deal with oxidative damage.

    So, if the cornea allows (its bandpass function, look it up) most of the IR radiation between 700nm and 1400nm, that radiation is passed directly to the aqueous humor and the retina. Once it reaches the retina, most of that energy is absorbed by the RPE or retinal pigment epithelia. The neural retina then is heated through conduction. The scary thing is that heating can happen in literally fractions of seconds. I did some consulting for the US military a few years ago where we discussed heating with respect to the proliferation of laser weapons on the battlefield and this is a big deal, particularly as many of the lasers and emitters are in the IR range covering near to mid IR. As I recall, the IR studies done on primates by the US Army revealed exposures from 700-1400nm took around 15 minutes to cause obvious burns which is why most optical coherence tomography devices have absolute limits on how long exams can take. However, those studies were gross clinical studies with no protein expression, metabolic or even histology that occurred, so we don’t really know yet what the exposure time is for damage to visual function. Psychophysics studies were not performed on those animals to my knowledge.

    As to the accusation of plagarism, its hard to accuse me of that when I cited the source in the previous paragraph and am in fact, the editor for that source… Webvision.

    Also know that many of the studies in the evolution of opsins were done by T.D. Lamb, whom you reference. By the way, Trevor Lamb is also a contributor to Webvision: http://webvision.med.utah.edu/book/part-xiv-evolution-of-phototransduction-vertebrate-photoreceptors-and-retina-by-trevor-lamb/ and his experience with the evolution of opsins and visual systems is unparalleled.

    Finally, to answer you question on co-authoring, I have never co-authored a work with Hunt.

    1. We look forward to you addressing the points mentioned in the above post. We actually want to talk a lot about these new things that you have brought up, but they don’t have to do with this project. Again. You mention that IR radiation and NIR is dangerous to tissues? You previously stated that pit vipers can sense IR from a meter away. People give of IR. Am I damaging my eyes by being near people? They do give off IR radiation. Or are you talking about highly focused IR energy, which is completely different? Are you just dumb-ing things down for us, because that’s not nice.

      As for your 6% original content score based on Google searching, we don’t care. We are obviously not your peer group. They care about that thing. They might take issue with you copy pasting their work and calling it your own. Being an editor doesn’t make you the owner of the work. Using 39 out of 40 words in a paragraph requires quotes. I am sure you can discuss that later with … not us. We don’t work in academia anymore, we don’t care. Sorry we pointed it out. We are, however, happy to link to the comment section of the forum when you frantically make excuses for the activity

      Please address the above, well referenced, points. Both in the original post and the new ones you have managed to bring up. No anecdotal references to working with the military. None of us can can check that information.

      1. Plagiarism checkers are readily available for anyone to use. The only way I was able to get the rebuttal article to “6% original content” was if I cut and paste it into a checker and then allowed the checker to count the original article as a duplicate. Even then it missed 6% of the “plagiarism”. You’re going to have to do better than than throwing out unsupported ad hominem if you want your response to the criticism to be taken seriously.

        You just spent over half your reply comment talking about the as yet unproven plagiarism while simultaneously claiming that you don’t care about it. The nasty language and ad hominem used in both this comment and the reply text above are unprofessional to say the least, but the fact that you don’t ever bother to back up this charge of plagiarism with any kind of evidence that the rest of us can see is beyond the pale. I’ve also read the other thread that you claim the critic was “frantically making excuses” in. He clearly referenced the source in the text, and the only claim you seem to be able to make is he should have also used quotation marks. Fair. But also nit picky and completely off topic. Beyond that I have yet to see you clearly show ANY evidence of the type of rampant plagiarism that you are clearly accusing him of. Pretending you are somehow above proving it, or “don’t care” is just a tactic to allow you to make ad hominem remarks, and to poison the conversation.

        Put up or shut up about this plagiarism charge.

        You can’t have it both ways, and bringing it up in the first place while continuing to reference it just makes it look like you have no actual rebuttal to the criticisms levied at you and are attempting to smoke screen that fact with irrelevant bluster. This is science. If you can’t take the heat then get out. Crowd sourcing does not mean you are allowed to be free of criticism, it means the opposite. You need to be ready for criticism before you even begin working on the project and before you are finished. Anything less just opens the door for charlatans to milk money out of lay people with promises of superhero powers.

        1. We welcome criticism. We are still looking forward to a response about the actual scientific points put forth in the above post. Are you seriously suggesting that because we called foul on his cut and paste technique, that all the other points are now invalid? Please explain to us how NIR causes the eye to boil (without lasers), or how over 50 years of journal papers refute his claims that they eye cannot see past 650nm.

          If you just cut and paste the quoted part of his rebuttal into Google, you find that it is directly taken from another persons work. You can do that with every piece of his breakdown about how the eye works. Expecting proper quotations and citing practices is not nitpicky. It’s expected.
          You are totally right, it wasn’t cool of us to do that. Also, no data was presented. Luckily, it’s not our point of focus. We are sorry we pushed a button mentioning plagiarism; I hear that can get you kicked out of school. I wonder what would have happened if I had put that in a term paper, the way it was written…

          And again, you are totally right, this is science. Could someone please talk about the actual scientific points made? It’s not a smoke screen, it’s justifiable frustration at someone not properly representing material that everyone here has looked over. We are just expecting someone, at some point, to discuss the literature.

          Here’s an abstract mentioned by Bill Rudersdorf in the comment section on Bryan’s rebuttal:

          “The Sensitivity of the Human Eye to Infra-Red Radiation
          Donald R. griffin, Ruth Hubbard, and George Wald

          JOSA, Vol. 37, Issue 7, pp. 546-553 (1947)

          Partial abstract:

          The spectral sensitivity of human vision has been measured in the near infra-red, in two areas of the dark adapted eye: the central fovea (cones) to 1000 mµ, and a peripheral area, in which the responses are primarily caused by rods, to 1050 mµ. In both cases the estimates of spectral sensitivity are based upon determinations of the visual thresholds for radiation passing through a series of infra-red filters. By successive approximation, sensitivity functions were chosen which were consistent with the observed thresholds.

          The spectral sensitivity of the fovea determined in this way is consistent with previous measurements of Goodeve on the unfixated eye. At wave-lengths beyond 800 mµ the periphery becomes appreciably more sensitive than the fovea. This tendency increases at longer wave-lengths, so that at the longest wave-lengths studied, the radiation appeared colorless at the threshold and stimulated only rods.”

          Here’s a selection from a text book:

          (Sekuler, R., and Blake, R. (1994). Perception (3rd ed.). Springfield, Ill.: Thomas.) pp. 62-63:

          “The following story dramatizes how photopigments determine what one can see. During World War II, the United States Navy wanted its sailors to be able to see infrared signal lights that would be invisible to the enemy. Normally, it is impossible to see infrared radiation because, as pointed out earlier, the wavelengths are too long for human photopigments. In order for humans to see infrared, the spectral sensitivity of some human photopigment would have to be changed. Vision scientists knew that retinal, the derivative of vitamin A, was part of every photopigment molecule and that various forms of vitamin A existed. If the retina could be encouraged to use some alternative form of vitamin A in its manufacture of photopigments, the spectral sensitivity of those photopigments would be abnormal, perhaps extending into infrared radiation. Human volunteers were fed diets rich in an alternative form of vitamin A but deficient in the usual form. Over several months, the volunteers’ vision changed, giving them greater sensitivity to light of longer wavelengths. Though the experiment seemed to be working, it was aborted. The development of the “snooperscope,” an electronic device for seeing infrared radiation, made continuation of the experiment unnecessary (Rubin and Walls, 1969). Still, the experiment demonstrates that photopigments select what one can see; changing those photopigments would change one’s vision.”

          Do you see how the points are made, and how we simultaneously used quote marks around the direct material copied? Both referenced and useful. Get upset about the plagiarism, don’t get upset, it’s all the same to us. But please, discuss the science. Anything less opens the door for entitled individuals with PhDs to start talking smack without doing their background work.

          We never promised superhero powers when we were crowdfunding, only that we would try.

  2. Wow. Brav fucking O guys.


    (we need experts fighting more often (not meant to be pejorative- very informative and I LOVED IT!)

  3. He lost me when he casually claimed that radiant heat (that can cross an absolute vacuum) doesn’t involve photons XD

    So even before your detailed discussion I wasn’t buying the rejection.

    The ratio between 850nm and upper end of red is considerably closer than the ratio between upper end of red and lower end of blue so the contention that NIR light is somehow different in nature from visible is spurious.

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