Last week I found myself sitting in the waiting area of a prominent eye clinic in Lusaka. Around me were people from every generation. Some hoped a new pair of glasses would sharpen the world again. Others were waiting to hear whether their eyesight could still be saved. It struck me that most of us only think seriously about our eyes once something has already gone wrong. Most of us assume that if we can still see clearly, our eyes must be healthy. We wait until road signs become blurry, we hold restaurant menus a little further away, or we blame tiredness after a long day in front of a screen. Yet our eyes are often telling us far more...