Columbia subject headings:
Art and science--History--19th century.
Impressionism (Art)
Optics and art.
Visual perception.
Harvard subject headings:
Art and science--History--19th century.
Impressionism (Art)
Optics and art.
Visual perception.
Princeton subject headings:
Art criticism--Europe--History--19th century.
Impressionism (Art)
Physiological optics--Europe--History--19th century.