Construction of Photochromic Ocular Contact Lenses with Superior Antibacterial Activity Derived from Polyoxometalate Nanozymes

Contact lenses exhibit outstanding practicality in vision correction and visual optimization owing to their inherent advantages, such as unobstructed clear vision, comfortable conformal fitting, aesthetic invisibility, and compatibility with daily activities. However, conventional contact lenses are prone to bacterial colonization, which can cause ocular infections and further induce keratitis. Herein, we designed and fabricated color-changing contact lenses based on polyoxometalate nanozymes for antibacterial and anti-inflammatory ocular therapy. In these contact lenses, polyoxometalate nanozymes can effectively achieve the catalytic decomposition of excessive reactive oxygen species to alleviate oxidative stress, while simultaneously inhibiting bacterial growth and proliferation. The immobilization of spiropyran imparts reversible photochromic properties to the contact lenses, which can effectively protect the eyes from ultraviolet damage. This design overcomes the drawback that conventional contact lenses easily induce ocular infections; more importantly, it constructs a multifunctional eye-protective system integrating antibacterial, anti-inflammatory and ultraviolet-protective functions.