Lee is a medical physicist, and until 2014 Director of the Medical Physics Department at Westmead Hospital, Sydney, Australia where he now has an honorary position. His interests are in laser and ionising/other non-ionising radiation safety, diagnostic radiology physics, and nuclear medicine.

Since leaving university in 1968, he has worked in hospitals in Australia and the UK, and during a radiation safety research appointment in Germany, became interested in laser applications in medicine. He is Chair of the Standards Australia medical laser committee which is responsible for a number of medical laser-related standards, especially AS/NZS 4173, and represents Australia on International Electrotechnical Commission committee TC76 which develops the international laser safety standards from which many national standards are derived. He is currently project leader for a joint IEC/ISO project developing a laser protective eyewear user’s guide.

Lee is  a Fellow and past President of the Australasian College of Physical Scientists and Engineers in Medicine (ACPSEM), an Honorary Fellow and past President of the Australasian Radiation Protection Society (ARPS), and the current non-ionising radiation ministerial appointee to the NSW Radiation Advisory Council. He has also performed many Technical Expert missions for the International Atomic Energy Agency in developing countries, predominantly teaching radiographers, radiologists and other interventionalists who use radiology imaging, in radiation safety and image quality in diagnostic and interventional radiology.

He was made a Member of the Order of Australia in 2003, was awarded a Distinguished Service award by the ACPSEM in 2002 and was given a 1906 Award by the International Electrotechnical Commission in 2013 and again in 2024.