Queen Elizabeth II's youngest granddaughter Lady Louise Mountbatten-Windsor has undergone surgery to correct a squint. The 10-year-old daughter of Prince Edward and Sophie, Countess of Wessex, has suffered vision problems since birth and underwent her first eye operation as a toddler. She has now undergone a second successful surgery to help correct her exotropia, a condition which causes the eyes to turn in different directions. Lady Louise is 10th in line to the British throne, and is the cousin of Prince George of Cambridge. She also acted as a bridesmaid during the wedding of his parents, Prince William and Catherine, Duchess of Cambridge.