What we can learn from nature to restore human vision

Abstract

Irreversible vision loss, affecting millions of people worldwide, most often ends in the death of retinal neurons that the human eye cannot replace. Across the tree of life, however, evolution has repeatedly produced strategies that address the core problems of vision restoration: zebrafish and salamanders regenerate functional retinas and lenses, and a wide range of species have tuned photoreceptors, optics, and neural circuits to extract maximal information from light. This review systematizes these biological strategies and evaluates how each is being translated toward human therapies, with grading of the strength of evidence behind every translational claim. We organize the field by biological strategy: regeneration, spectral tuning, low-light adaptation, high-acuity optics, polarization and additional channels, and neural processing, and for each trace the path from mechanism to therapy or device. The most mature translations are already clinical: gene therapy for inherited retinal disease, and optogenetic restoration of vision in blind patients. Regenerative approaches informed by regenerating species, including Müller glia reprogramming, ciliary marginal zone biology, retinal organoids, and stem cell transplantation, are advancing toward clinical feasibility. Spectral, low-light, and acuity specializations provide mechanistic blueprints and bio-inspired devices, though their biological translation to humans remains preclinical or theoretical. We conclude with the controversies, research gaps, and ethical considerations that will shape whether nature's strategies can be safely and equitably applied to restore human vision, and we briefly consider the evidence and limits of extending vision beyond its native range.