Free Color-Blindness Test from EnChroma

Available online and via app.

Big Picture

EnChroma, Inc., a California-based company that studies the feasibility of enhancing color vision in humans, has announced the release of a free Color Blindness Test for smartphones and tablets. Adults and children can take this test online at or by downloading the free app by searching for “enchroma” in their mobile device app store.

“In the diagnosis of poor color vision, the standard testing method requires a trip to the doctor’s office. This is the first time that a computer-based test is freely available that can accurately identify the type and extent of someone’s color vision deficiency,” says Don McPherson, PhD, vice-president, products, at EnChroma. “Thanks to a sponsorship by the National Institute of Health, I was able to create this app as a part of my National Eye Institute research project.”

The EnChroma test is based on a special kind of image called a pseudo-isochromatic plate. The plate has a random pattern of dots with varying size and brightness, to camouflage the appearance of a simple geometric shape in the image, which is a circle, a square, or a diamond. Because of the camouflage, the color of the dots is the only visual cue available to see the shape.

When the test starts, the hidden shapes are very easy to see because there is a large difference between the foreground and background colors. As the test proceeds, however, the plates get more challenging. At the conclusion of the test, the app provides the user with a diagnosis of their color vision including the type and extent of the deficiency, if any.

“More than 1000 people have already tested their vision since we posted our free test online,” says Andrew Schmeder, VP, technology, at Enchroma. “These early testers have been instrumental in adding to our understanding of the prevalence and severity of color blindness in the population.”


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