3D Corneal and Retinal Bioprinting: Tissue Engineering Strategies, Translational Challenges, and Clinical Opportunities

Three-dimensional bioprinting has emerged as a promising strategy for addressing major unmet needs in ophthalmology, including the global shortage of donor corneal tissue and the absence of restorative therapies for retinal degenerative disease. Advances in biomaterials, stem cell biology, and biofabrication have enabled increasingly sophisticated ocular constructs, ranging from engineered corneal grafts to multicellular retinal models that recapitulate key aspects of native tissue architecture. However, substantial challenges remain in reproducing the optical, mechanical, and biological functions required for clinical translation. This review critically evaluates the current state of corneal and retinal bioprinting through a framework organized around tissue target, fabrication modality, and intended application. Major bioprinting approaches, including extrusion-based, laser-assisted, drop-on-demand, and light-based technologies, are compared with respect to resolution, cell compatibility, scalability, and translational potential. Particular emphasis is placed on the engineering constraints governing construct fidelity, bioink design, tissue integration, and long-term functional performance. Current evidence suggests that corneal and retinal bioprinting have progressed along distinct translational trajectories. Corneal bioprinting has achieved encouraging preclinical outcomes, with selected approaches entering early clinical evaluation, whereas retinal bioprinting has generated highly informative disease models but remains at an earlier stage of translational development. Across both tissues, the field has increasingly shifted from reproducing individual cellular components toward reconstructing the biological interfaces and multicellular systems that underlie tissue function. Future progress will depend on establishing functional validation frameworks, reproducible manufacturing workflows, and standardized benchmarks to support the clinical development of vision-restoring bioprinted constructs.