Colored contact lens with all-weather humidity-triggered discoloration

Developing versatile printing inks with good biocompatibility is essential for the fabrication of functional colored contact lenses. In this work, by employing a new kind of printing ink that shows humidity-induced discoloration, multifunctional colored contact lenses have been constructed. The obtained products have displayed distinct and stable all-weather humidity-triggered discoloration under ambient conditions. More importantly, combined with a smartphone, the quantitative and qualitative relationship between the discoloration of colored contact lenses and environmental humidity has been established, which is expected to realize the early prediction of humidityrelated eye diseases in a portable, economical, and in-situ manner.