Recent quotes:

For Better Vision, Let the Sunshine In - The New York Times

Strong correlations were found between current eyesight and volunteers’ lifetime exposure to sunlight, above all UVB radiation (which is responsible for burning). Those who had gotten the most sun, particularly between the ages of 14 and 19, were about 25 percent less likely to have developed myopia by middle age. Exposure to sunlight up to the age of 30 also conferred a protective benefit.