When she entered medicine in the mid-1980s, Masayo Takahashi chose ophthalmology as her specialty, she said, because she wanted to have a family and thought the discipline would spare her from sudden work calls in the middle of the night, helping her best balance work and life.

Three decades later, the 55-year-old mother of two grown-up daughters is at the forefront of the nation's — even the world's — research into regenerative medicine.

In September 2014, she offered a ray of hope to scores of patients suffering from a severe eye condition when her team at the Riken institute's Center for Developmental Biology in Kobe succeeded in a world-first transplanting of cells made from induced pluripotent stem (iPS) cells into a human body.