Ho, Derek Kwun-hong http://orcid.org/0000-0002-6209-3594
Article History
Received: 6 August 2018
Revised: 19 November 2018
Accepted: 25 January 2019
First Online: 12 February 2019
Compliance with ethical standards
:
: I declare that the manuscript is original research, has not been previously published and has not been submitted for publication elsewhere while under consideration. I declare financial support in the form of Travel Award from the Worshipful Company of Spectacle Makers (WCSM) Education Trust (Registered Charity no. 1135045).