[1] Brien Holden Vis Inst, Sydney, NSW, Australia
[2] Univ New South Wales, Sch Optometry & Vis Sci, Sydney, NSW, Australia
[3] Univ KwaZulu Natal, African Vis Res Inst, Durban, South Africa
[4] Natl Univ Singapore, Singapore Eye Res Inst, Duke NUS Med Sch, Singapore Natl Eye Ctr, Singapore, Singapore