Poster Session: The optics of myopia onset and its potential impact on halting progression

Human genetics are the result of millennia of development with the eye optimized for outdoor vision. Recent changes in lifestyle have perturbed emmetropization and lead to frequent excessive eye growth. Myopia onset happens typically in school years when the process of emmetropization can be compromised. To prevent this from happening it is encouraged to spend more time outdoors. Being outdoors is associated with reduced dioptric demands, higher brightness and dopamine release, different spectral and special frequencies, and potential changes in choroidal thickness. Most apparent, outdoors the pupil size is smaller which narrows the pencil of light falling onto both the macula and the peripheral retina. This reduces the risk of light leaking out of cone and rod photoreceptors and thus maximizes the light capture efficiency of the layered visual pigments. Here, the role of pupil size is analyzed using ray optics for a schematic eye model and schematic elongated photoreceptors. Each photoreceptor does not perceive an image, but only operates to maximize its light capture. It is found that a 3 mm pupil is the ideal to prevent leakage of light from photoreceptors. Axial elongation moves the retina further away from the pupil thereby reducing the perceived solid angle at the photoreceptors. How these findings may impact on lens designs used to prevent myopia progression is discussed.