After graduating from the University of Sydney, Dr Sehu has spent nine years of specialist research, training and practice in the Sydney Eye Hospital and with advanced fellowships abroad at the Tennent Institute of Ophthalmology, University of Glasgow UK in ophthalmic pathology, oculoplastic surgery and ocular oncology. Returning to Sydney, he has become a staff specialist at the Sydney Eye Hospital where he also holds the title of Director of Eye Emergency and the co-Director of Training of Eye Registrars.

Teaching is an important activity for Dr Sehu and he has been an invited speaker to many ophthalmology, optometry, nursing and paramedical conferences in Australia and abroad. He is an examiner for the Royal Australian and New Zealand College of Ophthalmologists and for universities overseas. His most recent publication is the Eye Emergency Manual which was published by the NSW Department of Health, which is now used in most emergency departments within the country and it has also become the standard ophthalmic text for most medical schools in NSW. He is a Clinical Lecturer for the Dept of Ophthalmology, University of Sydney and holds a yearly course teaching ophthalmic pathology for Eye Registrars in Australian and New Zealand. Weng writes a monthly column for the Australian Doctor, a weekly magazine received by all Australian GPs. He has participated in volunteer ophthalmic work and teaching in developing countries. 

In addition to English, Weng speaks Chinese Cantonese and Mandarin as well Malay.