'We think of him painting the beautiful: Ginevra de’ Benci, Cecilia Gallerani and Salai glow with glossy hair and good bone structure. Yet alongside his fascination with youth and loveliness Leonardo was obsessed with irregular, diseased and aged faces whose “monstrous” distortions he drew with daunting precision.'

https://www.theguardian.com/artanddesign/2023/mar/15/mona-lisa-monstrous-grotesque-leonardo-da-vinci-national-gallery-ugly-duchess