“In his face and physique he was completely different from Philip, dissimilar even to his mother, and diverse in countenance from his reputed sire (Nectanebo); he was most handsome in his own way and his own style, with hair like a lion’s, slightly curling and tawny; his eyes were extraordinary beautiful, the right with a pupil that was almost black, the left blue-grey like the sky, absolutely filled with life and enrgy, like lions have, so that you should plainly see what nature promised about this boy. As he grew in bodily grace, so did he in knowledge and sagacity too.”

(Translation from Andrew Stewart’s Faces of Power: Alexander’s Image and Hellenistic Politics.)

This book is a variation on the Alexander Romance, much of which is pure fiction, so it’s difficult to accept this description of Alexander’s eyes, especially as there’s no similar reference in the traditional historical sources.