The EnChroma sunglass lens is based on an advanced optical coating technology that enables the lens to perform highly specific filtering of light reaching the eye. Unlike a conventional sunglass which simply reduces the transmission uniformly across the spectrum, the EnChroma lens is a “smart sunglass” that selectively filters the light to achieve an unprecedented super color enhancing effect. The wavelength-selectivity of the EnChroma filter is based on an advanced optical coating that far exceeds the capabilities of previously available methods.

EnChroma’s patent-pending coatings are designed using a proprietary computer-based optimization method. The method is based around a comprehensive mathematical model of the human visual system that enables us to predict the effect on color perception of any filter that is placed in front of the eyes. Using this tool, the unique filter that optimally provides the desired effect on color vision for an individual can be discovered and translated into a manufacturing specification.

To design a lens that helps people with color vision deficiency (also called color blindness), the mathematical model of vision is modified to account for the spectral changes associated with the specific type of deficiency. For example, in deuteranomaly, the M-cone sensitivity is shifted toward longer wavelengths. For protanomaly, the L-cone sensitivity is shifted toward shorter wavelengths. Then, the filter design that optimally enhances color vision for the individual can be analyzed and manufactured.

Color blindness can cause surprising problems with everyday tasks; for example picking ripe fruit at the grocery store or telling when meat is fully cooked. Red-green color blind people live in a world where people are expected to make certain distinctions that they just can’t: like reading maps and following road signs and signals. Even those with mild deficiency are slower and less reliable with color identification and are not able to fully appreciate the range of colors and textures found in the natural world.

In a clinical setting the performance of the EnChroma lens can be analyzed using the Farnsworth D-15 arrangement test. In this test, the patient is asked to order the colored caps in chromatic order.

Here we see the patient is red-green color blind. His ordering is significantly impaired. However, the ordering is actually a logical one from the subjects’ point of view—he has ordered the caps in order from blue-ness to yellow-ness, simply ignoring variation along the red-to-green direction of color space.

After wearing the EnChroma eyewear for an adaptation period of 30 minutes, the patient performs the Farnsworth D-15 test again.

We now can see that the arrangement has significantly improved. One subject accurately described the experience as a “new dimension of color”.

The color enhancing effect provided by these filters works by selectively blocking the wavelengths of light that contribute most to color confusion, thereby improving the signal to noise ratio in the chromatic channels. This makes color vision more reliable and color identification faster. This improves not only the clinical performance of the patient on the color arrangement test, but also greatly improves color vision in the real world.

The EnChroma Cx-D is designed for use with deuteranomalous color vision deficiency, a condition prevalent in about 7% of males worldwide. Deutans have a genetic anomaly that affects the M-cone (i.e., the green cone). Deutans typically have difficulty with differentiating between green and brow, green and yellow, and between pink and grey.

The EnChroma Cx-PT is designed for use with protanomalous color vision deficiency, a condition prevalent in about 1% of males worldwide. Protans have a genetic anomaly that affects the L-cone (i.e., the red cone). Protans typically have difficulty with differentiating between red and brown, green and orange, and between purple and blue. They often do not see the “red component” of colors, and reds appear to them as unusually dark.