Your ability to read the words on this page depends on the precise focus of each letter’s image onto the photoreceptors at the back of your retina. Maintaining proper focus is critical to vision, and we have evolved strategies to focus both dynamically – by adjusting our lens and pupil (accommodation) – and developmentally – by precisely regulating eye growth to match the optics of the lens and cornea (emmetropization). Because we rely on our high visual acuity to read and interact with our modern world, even minor dysfunction in these focus-regulation processes can lead to substantial deficits in quality of life.
Problems with the ability to focus are collectively called refractive disease, and the incidence of myopia, the most common refractive disease, has reached epidemic proportions, particularly in Asia/ More than 2 billion people are currently myopic, and that number is expected to rise to 5 billion (50% of the world population) by 2050. Importantly, myopia is more than just an expensive inconvenience that can be treated with glasses. Myopia increases the risk of a large variety of irreversible blinding diseases, including retinal detachment, and the incidence of ‘high myopia’, which cannot be corrected with glasses alone, has risen proportionally to the less severe cases.
Work in my lab has revealed a specific cell type in the retina that is exquisitely sensitive to defocus in an image (Bottom Left). My ongoing research will establish causal links between this cell and circuits for accommodation and emmetropization. Spanning multiple levels of analysis, I will measure gene expression and light responses in individual cells, trace specific connections from the retina to the brain, design a behavioral paradigm to watch animals focus in real time, and track eye growth over development. My interdisciplinary approach combines electrophysiology, genetics, pharmacology, circuit tracing, behavior, and development. By solving a decades-old mystery about how defocus is detected in the eye, I hope to usher in a new era of targeted interventions to bring the world into better focus for millions of people.