The power of CRISPR genome editing provides the exciting potential to cure retinal diseases with no available treatment. Dominant negative mutations cause Best disease, a retinal disorder that leads to progressive vision loss. We are optimizing the CRISPR-Cas9 genome engineering system to efficiently correct the disease-causing mutations in retinal cells while avoiding unintended genetic changes. We grow retinal cells from patient stem cells (iPSCs), allowing us to test editing methods in the patient’s own cells before a clinical trial. We are exploring delivery methods to introduce CRISPR editing molecules directly under a patient’s retina to fix the disease-causing mutation. These proof-of-concept studies will provide the first steps toward potentially vision-restoring therapeutic editing.