“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)

Actress Rosie Huntington-Whiteley arrives at the LACMA Art + Gala at LACMA on October 27, 2012 in Los Angeles, California. (Photo by Jon Kopaloff/FilmMagic)

Revellers take part in an annual block party before Carnival in downtown Rio de Janeiro, Brazil, January 16, 2016. The Rio de Janeiro Carnival will be held from February 5 to February 9. (Photo by Pilar Olivares/Reuters)

A cat receives acupuncture treatment in Shanghai, China on August 21, 2017. Traditional practitioners believe acupuncture of the body can stimulate blood circulation to promote healing and relieve some aches and pains. (Photo by Aly Song/Reuters)

A model presents a creation of YUKIHERO PRO-WRESTLING by designer Yukihiro Teshima from his Autumn/Winter 2018 collection during Fashion Week Tokyo in Tokyo, Japan March 20, 2018. (Photo by Issei Kato/Reuters)

Sabera Bayanne, 20, a student of the Shaolin Wushu club, practices in Kabul, Afghanistan January 29, 2017. On a snowy mountaintop to the west of Kabul, a group of Afghan girls practise the flowing movements of Wushu, a sport developed from ancient Chinese kung fu martial arts, stretching and bending and slashing the air with bright swords. (Photo by Mohammad Ismail/Reuters)

Devotees walk through the woods of Changu Narayan as they arrive to perform rituals and prayers during the Swasthani Bratakatha festival in Bhaktapur, Nepal February 8, 2017. (Photo by Navesh Chitrakar/Reuters)

Nepalese Mahuts with their elephant participate in elephant picnic as a part of the12th Chitawan Elephant Festival at Sauhara, Chitawan, some 154 kilometer from the capital of Kathmandu, Nepal, 28 December 2015. More than 80 elephant with their Mahuts joined the elephant picnic. The five-day festival began on 26 December to spread awareness about wildlife and promote tourism. (Photo by Hemanta Shrestha/EPA)