Scientists Develop Self-Repairing Contact Lenses That Fix Scratches With UV Light

Researchers in South Korea have engineered a groundbreaking type of contact lens that can mend its own scratches. This innovation addresses a common problem with soft contact lenses: the development of microscopic abrasions during daily handling and cleaning. These tiny scratches can potentially harm the eyes and impair vision. The new lenses, developed by chemists Jung-Hoon Choi and Byung-Ki Cho at Dankook University, utilize a special hydrogel material containing a disulfide cross-linker. This unique molecular structure allows the material to reform broken bonds when exposed to ordinary ultraviolet (UV) light, effectively repairing scratches within an hour. The study, published in ACS Applied Polymer Materials, details how the disulfide cross-linker, when activated by UV light, enables sulfur atoms to bridge gaps and reconnect fractured polymer chains. This self-healing process can restore approximately 90% of the material's structural integrity. Beyond their repair capabilities, the lenses also demonstrate comparable water retention to current soft contact lenses and exhibit remarkable scratch resistance. This suggests that the new lenses could be more durable and safer for users, potentially reducing the need for frequent replacements and minimizing waste.

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This work describes the synthesis, mechanical characterization, and functional evaluation of this disulfide cross-linked hydrogel system, as well as its application from hydrogel samples to a practical contact lens model produced by molding.