[1] Univ Western Sydney, Translat Hlth Res Inst THRI, Sch Med, Sydney, NSW 2560, Australia
[2] Univ KwaZulu Natal, African Vision Res Inst AVRI, Discipline Optometry, Westville Campus, ZA-3629 Durban, South Africa
[3] Univ Bamenda, Hlth Div, Bambili POB 39, Bamenda, Cameroon
[4] Univ Highlands & Isl, Ctr Hlth Sci, Dept Optometry, Inverness IV2 3JH, Scotland
[5] Univ Cape Coast, Sch Allied Hlth Sci, Dept Optometry & Vision Sci, Cape Coast 03321, Ghana
[6] Univ Jos, Dept Community Med, Coll Hlth Sci, Jos 930001, Nigeria
[7] Univ Jos, Dept Psychiat, Coll Hlth Sci, Jos 930001, Nigeria
[8] Univ Calabar, Fac Allied Med Sci, Dept Publ Hlth, Coll Med Sci, Calabar 540271, Nigeria
[9] Sch Management & Mkt, Curtin Business Sch Bentley, Perth, WA 6102, Australia
[10] Tanzania Food & Nutr Ctr, POB 977, Dar Es Salaam, Tanzania
[11] Mzuzu Univ, Dept Optometry & Vision Sci, Mzuzu 105200, Malawi
[12] Univ Jos, Dept Comp Sci, Jos 930001, Nigeria
[13] Univ Benin, Dept Optometry, Benin 300213, Benin
[14] Univ Western Sydney, Sch Hlth Sci, Sydney, NSW 2560, Australia