A new technology dubbed “achromatic metasurface” from Harvard’s SEAS aims at making Chromatic Aberration (CA), a thing of the past. Moreover, they are planning to do it with a flat lens design.
A flat lens prototype was introduced back in 2012, but it could only work with one wavelength creating significant Chromatic Aberration
The lenses we know are curved, making the acting like a prism and breaking different wavelength in different angles, creating an effect called Chromatic Aberration. Most lens companies have technologies to overcome this problem by either including several glass elements in the glass or by using different types of glass (like ED glass for Nikon).