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)

A leader “Rolli” of a yodel group “Schuppel” runs in the snow in front of a farmstead during the “Silvesterchlausen” in the early morning in Urnaesch in the Swiss canton Appenzell Ausserroden on January 13, 2017. (Photo by Michael Buholzer/AFP Photo)

A knife is seen beside a bowl containing blood after a ram was killed as a sacrifice in front of a shrine at the annual voodoo festival in Ouidah, Benin, January 10, 2016. In Ouidah, a small town and former slave port in the West African country of Benin, the annual voodoo festival gathers visitors from far and wide. It's a week that brings together priests and dignitaries, rich and poor, locals and visitors from as far afield as the Caribbean and France. The festival commemorates the estimated 60 million people who lost their homelands and their freedom during the African slave trade. (Photo by Akintunde Akinleye/Reuters)

In 2002 photographer Corey Arnold left behind a poor economy in San Francisco and headed up to Alaska to try his luck at his longtime passion of fishing. Arnold, who had worked summers during college on a salmon boat in Alaska, signed onto the f/v Rollo, a crabbing boat that fishes in the dangerous Bering Sea. While working long, strenuous hours on the Rollo, Arnold often stole away with the captain’s permission to grab his camera and photograph the crew and the ship. Arnold eventually put together “Fish Work: Bering Sea”, a documentation of his seven adventurous and dicey crab seasons aboard the Rollo. (Photo by Corey Arnold)

Members of a historical re-enactment group dressed as U.S. and Soviet Army soldiers take part in Elbe Day celebrations, in eastern German city of Torgau at the river Elbe, April 25, 2015. Elbe Day commemorates the encounter of the Allies 70 years ago, on the 25th of April 1945 when American and Soviet army units joined together on the destroyed bridge over the river Elbe. The photograph of the meaningful handshake made its way around the world and became a symbol of the near end of World War II in Europe. (Photo by Stefanie Loos/Reuters)

This green-skinned trio were happy to pose for the camera – with one little frog smiling happily for its close up. The three Reinwardt's Flying Frog, commonly known as the black webbed tree frog or the green flying frog, were spotted playing in a tree by photographer Hendy Mp. The 25-year-old who saw the frogs near his home in Sambas, Kalimantan Barat, in Indonesia, said they reminded him of three brothers playing together. (Photo by Hendy Mp/SOLENT News)

Intrigued by photographing time, Singapore-based photographer Fong Qi Wei created single, composite pictures from a sequence of images spanning 2-4 hours. He concentrated on capturing sunrises and sunsets as they evolved over different landscapes, seascapes, and cityscapes. He then digitally stitched the images together to get a snapshot of time passing over the scene for his series “Time is a Dimension”. “Most paintings and photographs are an instance of time”, Wei explained in his artist’s statement. “That’s not the way the world works. We experience a sequence of time, and that’s why a video is somehow more compelling than a freeze frame”. (Photo by Fong Qi Wei/Thoughtful Photography)