Of Eurasian descent, Sheares was born in Singapore under British rule and graduated from the King Edward VII College of Medicine.

He later became the Professor of Obstetrics and Gynaecology at the university, a rare feat for a local as usually high-ranking colonial officers held such positions.

During his presidency, he officiated multiple events and ceremonies such as the 1971 Commonwealth Heads of Government Meeting and the 7th South East Asian Peninsular Games.

The lower Caesarian section has since become the standard procedure in Singapore whilst his method to create an artificial vagina has been dubbed the Sheares operation and is used to help women suffering from Mayer–Rokitansky–Küster–Hauser syndrome.

[2][3][4] Known affectionally as Ben or Bennie when he was younger, Sheares showed ambition to become a doctor – a dream deemed almost impossible for someone who was Asian and came from a poor family in the early colonial days of Singapore.

However, his sister Alice encouraged him to follow his dream against his mother's wishes for her son to take up a job as a clerk and start helping out with the family bills as soon as he completed his Senior Cambridge Examinations (present-day GCE Ordinary Level).

In 1923, he enrolled into the King Edward VII College of Medicine (now the National University of Singapore) to begin his medical training.

During the war in 1941, whilst working at KKH, it was damaged by the bombing from the Japanese military and it was converted into an emergency general hospital for injured civilians.

Later during the Japanese occupation, Sheares served as head of department of Obstetrics and Gynaecology and Medical Superintendent for the local patients section of the hospital.

[11] He had planned to take an examination at the Royal College of Surgeons of Edinburgh to join the Fellowship of the Royal Colleges of Surgeons but returned to Singapore after being called by then-Governor of Singapore Franklin Gimson to return to his post as Acting Professor of Obstetrics and Gynaecology as the previous Professor had retired.

[5][10] With these referrals, Sheares met with the Selection Board in London and, in January 1950, became the first local Professor of Obstetrics and Gynaecology at the University of Malaya in Singapore.

[7][14] From 1953 to 1955, Sheares helped design new additions to the KKH building such as the out-patient department and the front block of the hospital, stating that, "[KKH] was initially just a maternity hospital and I had to design the new buildings in such a way that the maternity operating theatres were in a different block from the gynaecological operating theatres.

"[5] Sheares retired in June 1960 from the National University of Singapore as he was suffering from health complications such as gastric ulcers.

[21][22][23] Following the death of incumbent president Yusof Ishak, six people – Yeoh Ghim Seng, Othman Wok, Wee Chong Jin, Ismail bin Abdul, Punch Coomaraswamy, and A. P. Rajah – were considered to be the most likely candidates for the role in November 1970, given that the president was elected on by Parliament instead of by popular vote.

"[4] Speculation on why Sheares was chosen to become the president include that he was non-partisan, as he was not a part of any political party, or that he was from a minority race in Singapore, to show the equality in the then-mostly Chinese dominated government.

The Far Eastern Economic Review stated in a 1971 issue that Sheares was largely chosen due to his profession and success, along with showing diversity in the government.

[53] In September 1973, Sheares opened the 7th South East Asian Peninsular Games at the National Stadium as the host country.

[56] In July 1975, Sheares was made an honorary fellow of the Royal Society of Medicine by Sir John Stallworthy.

[60] In 1977, at the opening of the fourth Parliament, Sheares gave a speech addressing the economics and security of Singapore, stating that they have increased from prospects given in October 1972.

[75] In 1955, Sheares and his family were robbed in their bungalow, which was provided by the University of Malaya in Singapore, and had S$10,000 worth of jewellery and cash stolen from them.

[76] In November 1971, Sheares underwent medical treatment for a vascular disorder in the United States as the operation required had not yet been developed in Singapore.

Other visitors included Environment Minister Ong Pang Boon and Member of Parliament Lee Chiaw Meng.

[82] On 16 May, Sheares' coffin was carried from the Istana to Kranji State Cemetery to be buried where he was given a 21-gun salute by the Singapore Armed Forces.

[83] Foreign dignitaries who attended his funeral include Indonesian President Suharto, Thai Prime Minister Prem Tinsulanonda, Malaysian Deputy Prime Minister Mahathir Mohamad, Governor of Malacca Syed Zahiruddin Syed Hassan, and Filipino Speaker of the House Querube Makalintal.

Other countries such as New Zealand, Myanmar, Japan, South Korea, Brunei, Maldives, Nauru, Sri Lanka, United States, and Australia also sent their representatives.

Then-Yang di-Pertuan Agong of Malaysia Sultan Ahmad Shah stated that he was "an illustrious son of Singapore who had contributed much to the existing close relationship between [the] two countries.