Short-sightedness—myopia—is reaching epidemic proportions. Decades ago education seemed the culprit—too much reading. Then scientists blamed the computer. Reading more or spending more time at the computer should then lead to more myopia. However, studies showed it didn’t. New research points in an interesting new direction: the sun. Our eyes need more light; more outdoors. Three hours per day under light levels of at least 10,000 lux protects against myopia. (An overcast day can provide less than 10,000 lux and a well-lit office or classroom is usually no more than 500 lux.) And this is not a new insight. As Nature writes: Henry Edward Juler, a renowned British eye surgeon, wrote in 1904 in A Handbook of Ophthalmic Science and Practice that when “the myopia had become stationary, change of air — a sea voyage if possible — should be prescribed”.