Claude Monet

Claude Monet later in life he developed cataracts, the lenses of his eyes became yellow and cloudy. He mostly focused on the colour of his paintings, but because of his cataracts it would become a problem. Our eyes have three kind of cone cells. They are sensitive to blue, green and red light. However their sensitivity overlaps and because we're active in the day light, our eyes are most sensitive to yellow light. Because Monet's eyes were yellow, they acted as a colour subtracting filter. Taking away the blue and red light and enhancing yellow.

He painted a Japanese bridge over a lily pond almost every day to show the development of his eye sight.

His cataract got so bad that he decided to have his lens from his right eye removed. Our lens filter out the ultra violet light, but without it Monet could see half of his world in ultra violet, like a honey bee for example.

 One day he decides to show us a painting with his right and left eye, keeping one shut each time when he painted it. His left eye showed a muddy, red and yellow world while his right showed brilliant blues and violets.