Images from Scivias, which Hildegard almost certainly had a hand in, show a proliferation of concentric circles, jagged edges and black spots. Unusually, her illuminations include the use of both gold and silver, the metals creating the effect of ‘scotoma’ – shimmering and flickering areas of light and dark. The renowned neurologist Oliver Sacks began experiencing migraines during early childhood, around the same age as Hildegard did. His description recalls her visions almost exactly, including the range of colours, shapes and composition she included in Scivias:
