4D-printed photochromic contact lenses for ultraviolet monitoring and protection

Long-term exposure to ultraviolet (UV) radiation causes severe illnesses like pterygium, cataracts, climatic droplet keratopathy, solar retinopathy, and uveal melanoma. Occupational UV exposure is a significant concern for arc welders, laboratory technicians, and laborers directly exposed to sunlight. Here, we report photochromic contact lenses that change color in the presence of UV radiation. In addition to offering UV blockage, these contact lenses alert the wearer to UV hazards. The usage of photochromic dyes for UV protection is relatively recent, and there is great scope for further research in this field. The 4D-printed contact lenses developed here present strong optical, mechanical, and water absorption properties in addition to quick color transition and UV-blocking characteristics. Furthermore, multimaterial contact lenses with UV-monitoring rings enable smart monitoring and reporting of UV exposure incidents. These contact lenses can ensure better workplace safety by alerting and protecting individuals.