Additionally, it's now understood that insufficient exposure to very bright light (say, sunlight) during key years is the main risk factor for nearsightedness.

Additionally, it's now understood that insufficient exposure to very bright light (say, sunlight) during key years is the main risk factor for nearsightedness. Cutting time outdoors during Winter, for lower-elementary kids (K-2), when school is monopolizing a good portion of daylight hours, is almost certain to increase rates of nearsightedness. Cutting recess in young grades hurts kids' eyes, permanently.