“In anatomy, heterochromia refers to a difference in coloration, usually of the iris (but also of hair or skin). Although infrequently seen in humans, complete heterochromia is more frequently observed in other species, where it almost always involves one blue eye”. – Wikipedia (Photo by StooMathiesen)

At the 50th anniversary of the Hartford Automobile Club a 1914 Mercer with an economical wind screen, looking like a large magnifying glass, designed to offer minimum wind resistance. Brass is used instead of chrome for the “shiny” parts, circa 1955. (Photo by Three Lions)

Tiny pieces of space rocks, called meteorites, are seen burning in the atmosphere over the night sky near Salgótarján, some 109km northeast of Budapest, Hungary, 21 April 2018 (issued 22 April 2018). (Photo by Peter Komka/EPA/EFE)

A cockfight is seen at an event organised to celebrate the Lunar New Year and the year of the Rooster on the outskirts of Bangkok, Thailand January 29, 2017. (Photo by Jorge Silva/Reuters)

Residents watch the forest burn in Portezuelo, Chile, Sunday, January 29, 2017. Chilean President Michelle Bachelet has announced that the country will continue with its various measures to deal with wild fires, one of the biggest natural disasters in the country for decades, according to a government report released on Sunday. (Photo by Esteban Felix/AP Photo)

Underwater photographer of the year – winner. Dancing Octopus by Gabriel Barathieu (France). Location: Island of Mayotte, off the coast of south-east Africa. “Balletic and malevolent”, one judge said of this octopus, hunting in a lagoon. Barathieu waited until spring tides when there was just 30cm of water on the flats and plenty of light in the shallows. (Photo by Gabriel Barathieu/UPY2017)

Wildlife category, open shortlist. “Buffaloes and stars”. This picture, taken at Zimanga game reserve in KwaZulu-Natal, South Africa, used an in-camera multiple exposure, with the first lit for the buffaloes and the second focused on the stars. (Photo and caption by Andreas Hemb/2017 Sony World Photography Awards)

Christian Balderosdasco, 31, is being pulled up a mud pit after diving for 3 hours to look for gold on March 22, 2017 in Paracale, Philippines. Apart from tunneling and sifting sand, locals dive down murky swamps with the aid of a compressor with air flowing in a small tube for breathing, as they blindly swim under the mud for up to four hours to look for tiny rocks containing gold particles. For decades, local residents at Paracale town work in hazardous conditions scavenging under the earth and diving into tunnels filled with mud using only makeshift tools to mine for gold, often placing their health and lives at risk. (Photo by Jes Aznar/Getty Images)