These adorable cats – which are twins – showcase their contrasting blue and green eyes. The cats have a condition called heterochromia iridis, which causes each eye to vary in color. (Photo by @sis.twins/Caters News Agency)

Liverpool man has shocked people with his party trick of making his eyes bulge out of his head, now he hopes to join the record books. This eye-popping performer is fast becoming a YouTube hit as he tries to claim the official world record.

In this Thursday, April 11, 2013 photo, an Afghan woman peers through the the eye slit of her burqa as she waits to try on a new burqa in shop in the old town of Kabul, Afghanistan. (Photo by Anja Niedringhaus/AP Photo)

American singer Ashley Nicolette Frangipane, known professionally as Halsey wears eye-catching makeup to celebrate AF 94 in the last decade of July 2022. (Photo by iamhalsey/Instagram)

Fireworks explode around the London Eye wheel, the Big Ben clock tower and the Houses of Parliament to mark the beginning of the New Year in London, Britain, January 1, 2016. (Photo by Toby Melville/Reuters)

The double compound eyes of a male St. Mark's fly (Bibio marci), submitted by Dr. David Maitland from Feltwell, UK. (Dr. David Maitland)

Characters from Star Wars pose for a photocall to promote the release of Star Wars: Episode 1 – The Phantom Menace 3D at The London Eye on February 8, 2012 in London, England. (Photo by Dave J. Hogan/Getty Images)

Clutching a large paper bag and shading his eyes as he peers ahead, comic actor of the silent screen, Buster Keaton (1885–1966) arriving at Paris airport. (Photo by Keystone/Getty Images). 1st August 1947