Two colorblind brothers, Jimmy and Jace Papenhausen, were in for a surprise when their parents bought them a new pair of glasses. Jimmy’s dad was holding a handful of balloons, asking his son to name the colors. “Orange?” Jimmy answered. “It’s green,” his father replied.

Jimmy was then handed a pair of color-blindness glasses from EnChroma while onlookers held up balloons and a boldly colored beach towel. As seen in this heartwarming video, Jimmy was moved to tears. He handed the glasses off to his brother Jace, who was similarly overwhelmed. “It’s so bright,” he said.

They might look like sunglasses, but EnChroma’s product actually boosts the saturation of red and green light. That helps to improve color vision in people with red-green color-blindness, the most common color vision deficiency, affecting up to one in 12 men and one in 200 women (a true lack of color vision is very rare).

Most people have three types of color-sensing cones in their eyes: red, green, and blue. The wavelengths of light that these three cones absorb have overlapping regions. Color-blindness is often a result of a malfunctioning cone that causes wavelengths to overlap even more, resulting in poor color discrimination. The EnChroma glasses use a filter to cut out these overlapping wavelengths, allowing for a clearer distinction between colors, especially red and green.

The invention was derived from the work of Don McPherson, who earned his PhD in glass science at Alfred University. McPherson was trying to design protective eye wear for doctors performing laser surgeries. It wasn’t until he let a friend try on the glasses during a game of ultimate Frisbee that he realized the technology’s true potential. McPherson’s friend just happened to be color-blind, and the glasses gave both of them a shock.

That serendipity led to NIH-funded research for helping the color-blind. Early versions of the glasses were unsatisfactory, so McPherson began working with mathematician and computer scientist Andrew Schmeder to help optimize the glasses. In 2010, they cofounded EnChroma, and the first pair of glasses was released in 2012. EnChroma’s glasses cost around $269 for children and $349 for adults.

EnChroma’s website makes it clear that their glasses will not cure color-blindness, much as reading glasses won’t cure farsightedness. But a true cure could someday come in the form of gene therapy to deliver functional genes to the color-responsive cells in the retina. Jay Neitz, a professor of ophthalmology at the University of Washington, demonstrated the feasibility of this idea in monkeys back in 2009. And last year he teamed up with Avalanche Biotechnologies to try to move this technology into clinical trials.

Another caveat with EnChroma’s glasses is that they are not recommended for the color vision tests required for certain jobs, including operating ships, planes, and public transportation. A competitor, the ColorCorrection System, calls itself “the world’s only guaranteed color blind treatment that can ensure a passage of the Ishihara Color Test,” one of the most common such tests.

EnChroma is careful to avoid making such claims, but this also highlights the limited use of the product. Some people may find the price tag unjustifiable, but for others the dramatic effects are more than worth it.

(Read more: New York Times, NPR, “Color-Blind Monkeys Get Full Color Vision”)