New Delhi, Jan. 10 -- There aren't many scientists whose influence radiates so widely that millions benefit from their work without ever hearing their name. Yet that is precisely the impact Professor Tayyaba Hasan has had on the world.

Born into a Muslim family in Pratapgarh, India, she has lived all over Pakistan, and moved to America for her PhD. Over the past five decades, she has mentored hundreds of scientists. Her former students and postdocs are now scattered across the globe in what we call the "Hasan diaspora".

I have known Prof. Hasan since 2009 where we met formally at the 12th World Congress of the International Photodynamic Association in Seattle, Washington. We have been working together on the IPA Board for over the past ...