Claude Monet, a leader of the Impressionist movement, suffered from cataracts in both eyes during his later years. This medical condition significantly altered his perception of color. As the lenses of his eyes yellowed, his paintings began to take on muddier reds and yellows, and he struggled to see blues and greens. In 1923, he underwent surgery to remove a cataract. After the surgery, Monet reported that he could see ultraviolet light, which is usually filtered out by the human lens. This led to his final 'Water Lilies' series featuring vibrant, almost supernatural blues and violets that he hadn't used in years. His journey through changing vision is a fascinating example of how a physical condition can directly influence the aesthetic evolution of an artist’s work.