[1] Toronto Rehabil Inst, Mobil & Falls Clin, Toronto, ON M5G 2A2, Canada
[2] Univ Toronto, Fac Med, Dept Phys Therapy, Toronto, ON, Canada
[3] Hosp Sick Children, Dept Ophthalmol, Toronto, ON M5G 1X8, Canada
[4] Univ Toronto, Fac Med, Grad Dept Rehabil Sci, Toronto, ON, Canada
[5] Univ Waterloo, Dept Kinesiol, Fac Sci Appl, Waterloo, ON N2L 3G1, Canada