Last year, as our O2Amp technology got into the hands of more and more users (mainly interested in their various medical applications), we began hearing back from many color-blind folk.

One of our three technologies, they told us, gave them the surprising ability to distinguish reds and greens, exactly what their color-deficiency prevented them from seeing without our eyewear. In particular, the color-enhancing benefit came from our Oxy-Iso filter, which amplifies and isolates perception of oxygenation variations.

Although we didn’t design our technology with color-deficients specifically in mind, we weren’t too surprised that the Oxy-Iso may help with with red-green color-deficiency. As I have argued in my research and my earlier book, Vision Revolution, our human variety of color vision evolved — above and beyond that found in other mammals — in order to sense these oxygenation variations, allowing us to sense color-signals on the skin (including blushes, blanches, as well as sensing health). So the Oxy-Iso filter concentrates its enhancement exactly where red-green color-blind folk are deficient.

“…the Oxy-Iso lens blew me away. All of a sudden, the numbers just appeared on the screen!” Debra Miller Arbesman. And… “Your O2Amp glasses just nearly eliminated my wife’s color blindness! It was incredible to watch her take those tests.” - Samuel Arbesman, scientist, author of Half-Life of Facts, writer for WIRED

“In terms of the eye color charts, even the ones without numbers clearly had them; the ones with hard to discern numbers also jumped out.” - Greg Robie

“Without the Oxy-Iso he could “see” by tracing with his finger 4 of the Ishihara plates. After he could see all but 2 of the trickier ones and was able to trace those.” - Justin Nyquist

“I found the red one [the purple Oxy-Iso] to be useful (or, at least, the one that my wife tells me is red!). It makes many colors more vivid, although what looks white without them has just the slightest tinge of pink through the lens. Compared to the other two, it’s much closer to what I have imagined that “normal” people see, and the colors match up with what I’m told they are.” - Russell Belding

Now Professor Daniel Bor, a red-green color-blind neuroscientist at the University of Sussex and author of The Ravenous Brain, has independently carried out experiments on himself to gauge the extent to which the Oxy-Iso is an aid. The results are very encouraging, helping us better grasp its benefits, and also its limitations. Below I have reproduced his testimonial and the results of his experiment.


This first communication occurred after Dan received the set of three distinct O2Amp eyewear technology (and, note, he was not informed that it is the Oxy-Iso, and not the other two technologies, where we expected a benefit for color-deficients):

“I’ve just received a couple of special specs to attempt to reduce my colour blindness, from Mark Changizi and O2Amp. When I first put one of them on [the Oxy-Iso,], I got a shiver of excitement at how vibrant and red lips, clothes and other objects around me seemed. I’ve just done a quick 8 plate Ishihara colour blindness test. I scored 0/8 without the specs (so obviously colour blind), but 8/8 with them on (normal colour vision)! I’m pretty thrilled and can’t wait to explore more of the world with the specs over the next few days.”

We’ve found similarly thrilled responses from many other color-deficients as well (for a sample, see the quotes at the start of this piece).

Later, Dan carried out more formal experiments with the Ishihara plates…

In terms of formal tests, the Ishihara plates are a radical change. I did this online test of the 38 Ishihara plates: . Without [the Oxy-Iso], I scored almost nothing, but with the specs got all the answers correct, I think.

The Oxy-Iso appears to bring unambiguous red-green enhancement to color-deficients.

And, it even does so for the perception of oxygenation in the skin — “And definitely the glasses still work, even with me, for their original purpose of enhancing the appearance of veins,” writes Dan — meaning that the Oxy-Iso should aid the (red-green) color-blind in their perception of emotional and health states in others. Color-blind doctors have long been known to be handicapped at sensing health states, see Supplementary Table 1 here.


Our Oxy-Iso filter enhances red-green discriminations for color-deficients, but it does not do so without some compromises elsewhere in vision. We can see this clearly in Dan’s report…

“Having worn them for the evening, other parts of the spectrum definitely suffer – for instance, I thought the lime green light on the baby monitor was off when it was on. No problems seeing it when I took the specs off. But even if, having tried the specs for a few days (and especially outside in good daylight) I decide they aren’t worth permanent use, it’s been absolutely fantastic to get some temporary sense, for part of the spectrum, of what normal people see. For instance, having firmly believed that the light is green on the microwave I’ve had for 18 years, I’ve now discovered it is in fact blue.”


“My own experience with these specs is kind of similar to the formal results [see below]. Putting the specs on for the first time, I was amazed at how some colours really stood out for me. Lips usually almost seem similar to skin colour for me. But now they were so much more red and had a far greater contrast. Anything red was so much more vibrant and bright to me. Blue as well looked far more blue at times, especially if it previously had a greeny tinge to it for me. This was all very exciting. But also some colours looked a bit wrong. A yellowy-green light on my daughter’s baby monitor, easily seen without my specs, was now completely invisible. So some shades of yellow seemed to disappear with the specs, and so it was always clear to me that I had gained some part of the spectrum, but completely lost others, and on balance I kind of felt that I’d lost more than I’d gained. These wouldn’t be specs I’d wear all the time. But if I went to an art gallery or something like that, I’d definitely bring them with to wear then.”

This is important to emphasize: The Oxy-Iso filter amplifies the red-green discriminations color-deficients are lacking, but does so at the expense of their intact color perception and yellow-blue discrimination. In a sense, the Oxy-Iso spreads the color confusion more evenly around the color-wheel, rather than having it concentrated only on red-green. And, in this regard, the eyewear should not be worn when driving, because, for example, yellow lights will become nearly invisible.

[Note that our Oxy-Amp filter (see O2Amp) enhances color vision for color-normals, and does so not at the expense of other areas of color perception. Unlike the Oxy-Iso, the Oxy-Amp blocks only narrow wavelength bands of light responsible for noise coming from the oxygenation signals from skin. The Oxy-Amp provides a strict improvement to color vision for color-normals.]


The Ishihara test helps gauge one’s deficits in discriminating between reds and greens, but doesn’t tell us what’s happening to color perception more broadly. From Dan’s (and other’s) first-person experience, it is obvious that other aspects of color perception are hindered by the Oxy-Iso, as we just saw above. To get clearer on these deficits, Dan took what is called the Farnsworth-Munsell test…

“So I got one of my interns to do a proper Farnsworth-Munsell test in the lab with the physical discs, so this should be much more reliable. That was surprisingly disappointing. Without the specs I scored 116, so clearly in the colour-blind range, but with the specs I scored 108, only slightly better and still very much within the colour-blindness range. I’ve attached the graphs of my pre (no specs) and post (specs) results on this test for you to have a look at.

Remember, this test measures one’s overall deficit in color. Because the Oxy-Iso enhances red-green discrimination but at the expense of yellow-blue discriminations, it is not too surprising that the overall score here is not too much different.

The Oxy-Iso‘s ability to somewhat spread red-green color-deficient’s deficits more uniformly around the color wheel is visible in the plots of Dan’s experiment. This first plot below shows where he has trouble making color-discriminations with his naked eye, and one can see two regions opposite one another where he has trouble, characteristic of (one variety of) red-green deficiency.

naked eye

With the Oxy-Iso eyewear on, however, the characteristic red-green deficit is dampened considerably, but now there are new deficits (especially in the yellow regions), as you can see in the plot below. Compared to the plot above, the one below looks more rounded and evenly distributed.



With the caveats and limitations in mind, the Oxy-Iso provides many red-green color-blind people with a revelatory insight into a perceptual dimension they have thus far lacked, the emotional and vitality-laced perceptual color dimension that is new to us humans and some other primates.

First appeared on The Changizi Blog, January 29th, 2013