The philosopher Jeremy Bentham had "a penchant for showing dinner party guests the two glass eyes he kept in his pocket."

"The eyeballs were part of a larger project: Bentham wanted his body publicly dissected; his skeleton cleaned up, fully articulated, and padded with straw; and his head mummified for display. He would be, he said in his will, 'the Auto-Icon,' visited by friends or occasionally wheeled out for gatherings and parties.... Bentham had asked a friend, Thomas Southwood Smith, to embalm his head using traditional New Zealand Maori methods. The process—he was essentially smoked, and fitted with the eyes from his pocket—didn’t work as hoped."

So the head isn't kept on display with the rest of his body (which sports a wax head), but you can see a photograph of the head — with its brilliant blue glass eyes — at "Jeremy Bentham’s Head Is Coming Out of Its Box and Under the Microscope/Scientists want to know if the forward-thinking philosopher had autism" (Atlas Obscura).