A population-based study demonstrates more rapid progression in eyes without protection.
"Increased time spent outdoors during childhood is known to dampen the progression of myopia, but mitigating against this advantage of the great outdoors is concern over exposure to ultraviolet light—including its effect on refractive status. This study found that UV exposure might be a risk factor for myopia progression. Patients who wore UV blocking lenses over time appear to have less myopia progression both by sex and degree of myopia. Considering UV protection may be one more way that practitioners may be able to help control for myopia.”