The current treatment methods for bacterial keratitis, ranging from local antibiotics to corneal suturing and transplantation, have failed to simultaneously address infection control, inflammation regulation, and tissue regeneration. To balance the effective antibacterial effect with host tissue protection, we have developed an injectable biomimetic composite matrix that integrates a photosensitive collagen/hyaluronic acid-nitrobenzene conjugate (CHB) hydrogel with multifunctional carbon dots (CDs) derived from curcumin and several-cell sponges (CC-CDs). After injection, the CHB hydrogel forms a transparent adherent interface in situ, while CC-CDs utilize cationic shell-cross-linked polysaccharides for targeted bacterial membrane disruption and achieve intracellular redox homeostasis through curcumin-derived nanoenzyme activity. Notably, the water solubility of CC-CDs is over 4000 times higher than that of the hydrophobic curcumin, significantly enhancing its antioxidant efficacy and achieving a nearly complete elimination of bacteria while maintaining over 98% cell survival rate. Due to its biocompatibility, the composite hydrogel further promotes the polarization of macrophages towards the regenerative M2 phenotype. In vivo tests show that the bacterial load is reduced by 90% within 24 hours, the recruitment of anti-inflammatory cells increases by 6 times on the 4th day, the fibrosis markers are inhibited by 91.8%, and the retinal signal amplitude recovers by 87.5% on the 28th day. These findings highlight the synergistic ability of the composite hydrogel in scar-free structural repair and achieving visual function recovery through minimally invasive microenvironment regulation, establishing an alternative to traditional ophthalmic surgery. This study was published in ACS Nano under the title "Enzyme-Mimetic Hydrogel Balancing Antibacterial Activity and Cytoprotection for Corneal Regeneration in Bacterial Keratitis".