There are those among us who are “health blind”, i.e., handicapped at sensing the health signals most of us easily recognize on others around us. They are the color blind. But we at O2Amp can fix that.

1. The Health-Blind Among Us

Despite the presence of modern electronic medical sensing tools, medical personnel still rely on their naked-eye visual skills when examining and judging the symptoms and health of patients (Savin et al. 1997).

But it is not widely appreciated that approximately 5% of medical personnel – 10% of men and 1% of women – are “health blind”, i.e., they are severely perceptually handicapped at sensing the health symptoms of patients. And they – and those that hire them – often don’t even realize.

Who are these “health blind” medical personnel?

Although not widely appreciated, it has long been documented that red-green color-deficients are disabled at seeing veins, vasculature, pallor, cyanosis, jaundice, rashes, bruising, erythema, retinal damage, ear and throat inflammation, and blood in excretions (Dalton 1798; Wilson 1855; Best&Jaenel 1880; Little 1881; Ahlenstiel 1951; Logan 1977; Voke 1980; Steward&Cole 1989; Spalding 1993, 1995, 1997, 1999, 2004; Currier 1994; Anthony & Spalding 1999, 2004; Campbell et al. 1999, 2004, 2005; Reiss 2001; Cockburn 2004; Cole 2004; Changizi et al., 2006, suppl Table 1; Spalding et al. 2012). Even 18th century scientist John Dalton, who was color blind, observed that he “could scarcely distinguish mud from blood” (Dalton 1798).

Even today 10% of the 500 most prevalent medical conditions list skin color changes amongst the symptoms (Changizi & Rio 2009), and a red-green color deficient’s deficit in discriminating reds and greens makes him or her unable to see these everyday health color signals on the skin.

Color deficiency can consequently lead to medical misdiagnosis (Campbell, 1999; Campbell et al., 2004, 2005), and has at various times prevented entry into medical school (Hiroshi, 1998).

If you’re red-green colorblind, then you’re health-blind. And among those not traditionally deemed color deficient, many are mildly so, and thus mildly health-blind.

The graph below shows the reported clinical difficulties among 42 color-deficient doctors surveyed by Spalding (1995). (It should be kept in mind that this particular graph shows reported difficulties, and thus does not capture what the color-deficient doctors don’t realize they’re missing.)

Self-reported clinical perception difficulties from 42 color-deficient doctors (Spalding, 1995).

Self-reported clinical perception difficulties from 42 color-deficient doctors (Spalding, 1995).

2. Color-Deficiency is an Especially Severe Problem for the Medical Profession

A variety of occupations (e.g., pilots, police) routinely require passing a color exam before entry, and in some countries passing a color exam is even required in order to get a driver’s license.

But, except in rare instances (e.g., Hiroshi, 1998), color blindness had not been a formal barrier for becoming a doctor.

Unfortunately, a recent discovery by researchers at our 2ai Labs ( ) shows that color blindness is not just a problem for medical personnel, but a disproportionate problem for the medical community.

In 2006, we showed that color vision evolved specifically to distinguish health and emotion states on the skin: our peculiar primate variety of color vision evolved to be optimized for sensing the oxygenation modulations hemoglobin undergoes under the skin (Changizi et al., 2006).

Red-green color vision is uniquely about seeing oxygenation, and therefore red-green color-deficients are especially hindered at seeing the skin signals that underlie health signals. Unlike other fields where colorblindness is a handicap but where it is actually fairly unlikely to find perfectly indiscriminable colors to a color-deficient, the oxygenation variations of blood under the skin are completely invisible to the red-green colorblind because they’re missing the evolved machinery specifically designed to detect it.

Color blindness is consequently a critical issue in clinical settings for patient health. Approximately 5% of clinical personnel are handicapped at detecting everyday health signals on the skin (including seeing veins, for example), and yet many are not even cognizant of their handicap. (And neither are the many other personnel who are only mildly color-deficient (sometimes due to aging).)

Color deficiency is also a serious liability issue for medical staff and their employers, and color deficient doctors have been sued on this basis (see citation to News & Observer).

3. The O2Amp Medical Solution for Color-Deficiency

Historically there has been no solution for the color deficient clinician. Varieties of filtered eyewear for color deficients exist that can help them pass Ishihara tests or perceive certain discriminations among objects in the world. But none were designed to enhance the signal that primate color vision evolved to detect: oxygenation variations in the skin (Changizi et al., 2006). And thus no previous color blindness treatment was consistent with the health perception demands of medical personnel.

We at 2ai Labs, having discovered the evolutionary function of color vision, were in the unique position to design optical technology to enhance the signal for which color-deficients are deficient. In particular, we created O2Amp, our company highlighting several distinct optical technologies for enhancing perception of facets of the blood under the skin.

For color deficients our flagship technology is our Oxy-Iso Colorblind Correction Medical Eyewear, designed to amplify and isolate the oxygenation signal coming from under the skin. Color-normals use the eyewear to enhance perception of veins, but color-deficient medical personnel use the eyewear to amplify their minimal baseline sensitivity to oxygenation variations in the skin.

The Oxy-Iso doesn’t merely aid color deficiency…

…the Oxy-Iso aids color-deficiency in a manner consistent with the symptom-, vasculature-, and health-perceptual needs of doctors, nurses and other medical personnel.


[See O2Amp’s site – – for testimonials and more information. Also see the following for example results on the Farnsworth-Munsell Test: ]

“I wanted to let you know how much I have enjoyed using your eyewear, especially the Oxy-Iso glasses. I now use them in all of my leg vein procedures. Being color blind makes finding deeper (reticular) cutaneous veins a challenge; the Oxy-Iso eyewear makes them much easier to see… We actually have the Christie Vein Viewer (one of the IR devices) in our office… Although it is a very cool product, it does markedly alter the appearance of veins and the treatment process itself. While I haven’t used the IR device much for sclerotherapy, I use my Oxy-Iso’s every single time.” – Daniel Friedmann, MD, Cosmetic Dermatologic Surgery

“This is exciting. I have not been able to see colors my entire life… They really work. I recommend them.” – Cary M. Silverman, MD, ophthalmic surgeon, Eyecare 20:20. Video review.

“I had to try them, working in the Dental field, colors are very important in many aspects of my practice. They vary from instruments identification, diagnosis of the oral cavity, and many other aspects. I went from the muted colors that I was used to all my life, to what I perceive as a more bold, and brighter red and greens. To me the darker red shades, like maroons and burgandy colors are more lighter with the oxy-iso on. I went from not seeing any numbers on the online color blindness tests, to seeing most of them. It has been stated that there may be some limitations of these online test due to screen settings and ambient light. But going from seeing nothing to almost all of them is truly remarkable to me.” – DKH, DDS, Glen Cove

“After 20+ years of medical education, I had a healthy skepticism about these glasses. I mean, how can you “cure” color-blindness, my cone cells have a mutation and my brain has learned to adapt. My eyes simply can’t absorb light at those frequencies. But, I was intrigued. As a surgeon, being color blind has not affected me as much as you might think, texture is very important, as is consistency, and I think I rely on those cues all the time. However, I do have a problem telling if something is bile-stained versus just bloody, and dark bloody emesis I could only tell by the smell. But as an art lover, and flower lover, being color blind is just annoying. Not to mention trying to shop at places like J. Crew where all the stupid colors are like, “stone” and “sledge”. What? // Anyway, I bought these on a lark, and OH MY GOD, THEY WORK!!! I only get 1 right on the Ishihara color blindness plate test (red-green and some blue-yellow deficiencies), but with these glasses, I got more than half right! It makes everything brighter and so much more intense! I scrolled through a website of Impressionist paintings and it was incredible! Beautiful!! I can see red flowers on trees now!! I can see the red on birds’ wings!! it’s actually almost overwhelming, I don’t wear them very often because it makes me a little sad that I’ve lived 44 years with a muted palette. I haven’t tried them in the OR yet, but I’m on call Wednesday. . . Makes me wish I’d invented or invested.” – Dr. Marie Crandall, Associate Professor of Surgery, Northwestern University Feinberg School of Medicine

“Currently, I occasionally try them during orthopedic surgeries, but mostly during speys and castrations. Some of the pregnant or recently pregnant dogs/cats (especially cats) have large networks of enlarged superficial vasculature just beneath the skin, and the glasses can be beneficial in identifying and avoiding these during the initial incision.” - Dr. Aaron Raney, color-deficient veterinarian.

Originally appeared on The Changizi Blog.

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