The contest began in 2007, and since then photographers from more than 70 countries have entered. Photo: Michael O'Neal of San Francisco won first place in the animals category in the 2014 iPhone Photography Awards. (Photo by Michael O'Neal)

Afghan paraglider Leeda Ozori, 21, walks after practicing in Kabul, Afghanistan September 14, 2015. She is one of a group of young Afghans taking to the skies of a capital where military helicopters and surveillance balloons are a far more familiar sight. Women in Afghanistan's conservative Muslim society are increasingly entering areas such as education, sports and the workplace, but most still wear the head-to-toe garment, the burqa. (Photo by Mohammad Ismail/Reuters)

Visitors walk past "Sculpture #1" by Darren Bader at the Frieze Art Fair in London, Britain October 14, 2015. The Frieze Art Fair, which is one of the world's leading contemporary art fairs, opens today and runs through October 17. (Photo by Suzanne Plunkett/Reuters)

A man walks past an advertisement sign promoting a bank in Seoul in this September 3, 2009 file photo. South Korea is expected to release GDP dara this week. (Photo by Lee Jae-Won/Reuters)

A worker refreshes himself with a fan after loading a container with rice bags at an export plant in the central Chainat province in Thailand, December 16, 2015. (Photo by Jorge Silva/Reuters)

Members of the Bolivian combined forces of army and police rest at their headquarters at the end of their ceremony for the task of fighting against drugs and the eradication of coca leaves in Chimore, east of La Paz, December 10, 2014. The government of Bolivia's President Evo Morales eradicated some 11,000 hectares of illegal coca plants and confiscated nearly 192 tons of drugs in 2014, according to the local media. (Photo by David Mercado/Reuters)

French twins Thomas and Vincent (L) Seris take the tram in Bordeaux, November 12, 2014. Born with Xeroderma Pigmentosum (XP), the twins cannot be exposed to the sun and its ultraviolet (UV) light, which could provoke precocious cancers due to an autosomal recessive genetic disorder of DNA repair. Colloquially referred to as Children of the Night (Les Enfants de la Lune) the Seris twins are among 70 to 80 people in France who suffer from the genetic defect. The French association “Les Enfants de la Lune” reports that there are between five and ten thousand such cases in the world. Thomas and Vincent have been testing a new protective mask for the last year which is transparent and ventilated and developed by several hospitals in France. (Photo by Regis Duvignau/Reuters)

A woman (L) places flowers at a grave next to a mummified body during exhumation works at the General Cemetery in Guatemala City, April 15, 2015. If a lease on a grave has expired or not been paid, grave cleaners will break open the crypts to remove and rebury the bodies. Any remains that have not been claimed are packed into plastic bags, labeled and stored in mass graves. Bodies that have been stored in the upper crypt are exposed to dry and sunny conditions which means they do not decompose and instead become mummified. (Photo by Jorge Dan Lopez/Reuters)