Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Blindness is defined as the inability to see. Millions of people globally are affected by this type of visual impairment and, according to statistics, 90% of blind people live in developing countries. Blindness is a medical condition that considerably affects one's ability to perform everyday tasks, however, medics state that three quarters of all blindness can be prevented or treated. Learn more about blindness, its causes and management in this book.