High-tech contact lenses correct color blindness

Researchers have incorporated ultra-thin optical devices known as metasurfaces into off-the-shelf contact lenses to correct deuteranomaly, a form of red-green color blindness. The new customizable contact lens could offer a convenient and comfortable way to help people who experience various forms of color blindness

Based on simulations of color vision deficiency, the new metasurface-based contact lens can restore lost color contrast and improve color perception up to a factor of 10.

The approach used to introduce new and tailor-designed functionalities to contact lenses could be expanded to help other forms of color vision deficiency and even other eye disorders.

Deuteranomaly, which occurs mostly in men, is a condition in which the photoreceptor responsible for detecting green light responds to light associated with redder colors. Scientists have known for more than 100 years that this vision problem can be improved by reducing detection of the excessively perceived color but achieving this correction in a comfortable and compact device is challenging.

The researchers tested the optical response of the metasurface after every step of the new fabrication procedure and acquired microscopy images to closely examine the structure of the metasurface. Their measurements showed that the metasurface's light manipulation properties did not change after transfer to the curved surface, indicating that the process was successful.

The researchers then used a standard simulation of color perception to quantify the deuteranomaly color perception before and after introducing the optical element. They found an improvement of up to a factor of 10 and showed that visual contrast lost due to deuteranomaly was essentially fully restored.