20/20: What drives EnChroma?

At EnChroma, we strive to create lenses that are engineered using a rigorous evaluation framework. This produces lenses that are mathematically optimized for a color blind person’s specific type and extent of color vision deficiency. An advantage of our design process, which is based on computer simulations of how color blind people see color, is that it allows us to model the efficiency of many different potential solutions in parallel, including evaluation of different optical technology platforms. This enables us to continuously improve our core technology as new insights and material science developments are discovered. We are now producing our third-generation eyewear, which are available in both outdoor (sun) and indoor versions, as well as with prescriptions and custom edging into the patient’s own frame.


What was the discovery that lead to this unique invention?
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Over 10 years ago, Dr. Don McPherson, EnChroma chief science officer, had invented a special lens to protect the eyes of surgeons while performing laser surgery. This lens was groundbreaking in that it was able to provide the laser protection needed without the compromise to color vision from which conventional protective lenses suffered. Through a serendipitous event, he discovered this color transformation effect could also be a harness to assist the vision of a person with color blindness. One day, Don was wearing his glasses at an Ultimate Frisbee tournament (being both an athlete and an inventor) and showed these glasses to a friend who tried them and exclaimed, “Wow, I can see the cones!” It turns out his friend was severely color blind and couldn’t see orange field-marking cones against green grass. That was the “ah-ha” moment, which led Don to write an SBIR grant which was funded by the National Eye Institute for two phases. SBIR grants are a great way to get innovative ideas off the ground without taking dilutive venture capital dollars.


Why are people color blind?
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Human color vision works by making very fine comparisons between the relative stimulation of neighboring cone cells in the retina. Cone cells are classified, generally, by their predominant wavelength of light absorption. The S-cones respond to short wavelength or predominantly blue light, the M-cones to medium wavelength (green) and L-cones to long wavelength (red). By comparing the relative amount of stimulation between neighboring cones (e.g., M versus L), the brain receives information about the spectrum of light, which we perceive as color.

People with color blindness have a genetic substitution at one or more locations on the X-chromosome, which causes the absorption wavelengths of one of their cone classes to be shifted. For example, it can cause the M-cone response to shift toward a longer wavelength or the L-cone to shift toward shorter. When this shift exists, the amount of difference in stimulation of neighboring cones is decreased, causing a reduction to sensitivity of color differences in the eye of the observer.

What many people don’t understand is that color blindness only affects certain pairs of colors. For example, confusion between blue and purple is a typical symptom. Another one is pink versus white. These confusions don’t correspond to different types of color blindness; they are consequences of the underlying genetic differences in how that person’s eye is constructed.


Is all color blindness the same?
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Color blindness can be classified by type and severity. Usually “color blind” refers to so-called red-green color blindness, of which there are two types. “Deutans” have a substitution that causes the M-cone response to be shifted toward longer wavelengths. “Protans” have an L-cone substitution shifted shorter. These two types of color blindness have similar symptoms with respect to common color confusions, however, the Protan type is typically more severe because, in addition to the increased red-green (M-L) overlap, they also see red colors as darker. Color discrimination declines in low light because the perceptual mechanism is limited by noise in the neural circuitry.


How do EnChroma glasses work?
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A red-green color blind individual has an “excessive” overlap of the M and L cones, reducing each of the red and green cones’ effectivity by themselves. This reduces the ability to perceive color differences that rely upon the middle versus long wavelength spectrum components.

EnChroma lenses selectively filter out wavelengths of light at the precise point where maximum overlap occurs. As a result, the amount of stimulation to the M- and L-cones is altered such that there is a greater amount of difference. The result is an increase in color discrimination along the so-called “confusion line” for that individual.


Do they work for everyone that is color blind?
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Color blindness is not a singular condition—it encompasses a range of conditions that each see differently, both due to the physical characteristics of the retina and eye, as well as lifestyle preferences and subjective experiences of color that are highly individual.

Thus, we see a range of responses to the EnChroma experience, only some of which can be predicted from a color vision test score. However, having interacting thousands of people with color blindness, I think we have a unique insight into what the nature of this condition is, and based on the number of testimonials and recommendations we are getting, it is clear that we are on the right path toward our mission, which is to provide meaningful assistance to the vision of all people with any form of color blindness.


What are the obstacles in trying to introduce this kind of product?
There are many challenges, but one of the biggest is simply the lack of awareness of the issue. Color blindness is a “hidden” disability. It is not something that manifests itself in obvious ways, and it is easy to hide and ignore it. Ninety-six percent of the world is not color blind and goes about life without thinking about the potential consequences to the other 4 percent who might not see things the same way. It is also neglected by the school systems—even though we know that it has detrimental consequences to learning for kids and in limiting career choices, there is no mandatory testing in the majority of school districts. When I talk to kids with color blindness, the first question I ask is, “Does your teacher know you are color blind?” It is amazing how often the answer is “no.” Therefore, it is critical to EnChroma that our mission includes outreach and education so that more people become aware of what it means to be color blind and begin to think intelligently about appropriate methods to manage it.


How do you know that someone is actually seeing in color?
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Many people ask how we know that color perception is actually being improved by our glasses, but question what that actually means, and how we can know if the experience maps onto some kind of objective definition of “normal.” In other words—is my red the same as your red?

A color, say red, is not an isolated perceptual phenomenon. It exists within a framework called a “color space.” This is like a map that corresponds to the perceived similarities and differences between all the colors. In the case of color perception, we ask questions about the perceived distances between pairs of colors. That reveals what a person’s internal map looks like. Where some have gone wrong is by not asking enough questions to unambiguously establish what the map looks like. For example, a simple red-tinted lens certainly makes a color blind person see red, but it does so at the expense of other colors and causes an overall imbalance of the spectrum. You have to look at the perception of all pairs of opposing colors, in addition to their relation to brightness, to ensure that one is not confusing a change in brightness contrast with a change in color contrast. Color is defined as the property of light independent of its brightness.

An important detail to note is that our lenses do not “cure” color blindness. What our lens delivers is a changed enhanced experience that empowers people to make color a part of their daily life and experience, instead of eschewing it. Color identification and specific tasks is only one aspect of vision—ultimately, it is not just about seeing color but seeing and understanding the world in which we live, defined in many ways by the use and role of color.


We’ve seen the numerous “reveal” videos in social media where a family presents the EnChroma glasses as a gift and captures their first reactions. How did this trend start?
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Oscar Wilde wrote, “Color can speak to the soul in a thousand different ways.” Color has always been considered an emotional sense, perhaps because of its seeming intangibility. The popular evocative videos of people trying EnChroma glasses for the first time was something that started organically and turned into a trend because people wanted to share that moment. However, I also try to remind people that color is an individual experience, and not everyone will have that “YouTube moment.” Similar to adapting to a progressive lens, many people have told us their appreciation of the EnChroma lens technology actually takes time to develop.


You are currently an e-commerce business. How does this fit with the growing number of brick-and-mortar” eyecare professionals that also sell your products?
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We have always seen the eyecare professional as a key partner in our mission. However, color blindness is actually a niche market spread out globally. The power of e-commerce to reach niche markets is amazing and is going to rapidly accelerate our ability to make an impact on the lives of the millions of people with color blindness. In parallel, we are bringing on board and training eyecare professionals as fast as we feel we can reasonably accomplish this without taking shortcuts.


What can we expect from EnChroma in the future?
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We are continuing to explore product innovations that leverage our advanced optics expertise focused on color blindness. In addition, we will continue to work with and grow our distribution network and relationships with eyecare professionals around the world.