“…Based on review of existing pediatric vision questionnaires (Angeles-Han et al, 2011, Borsting et al, 2003, Carlton, 2013a, Cochrane et al,
2011, Cole et al, 2001, Felius et al, 2004, Gothwal et al, 2012, Hatt et al, 2010, Holmes et al,
2006, Hrisos et al, 2004,
Khadka et al, 2010, Sabri et al, 2006, Sacchetti et al, 2007, Tadic et
al., 2013) and other data on response options, (Khadka et al, 2012a) we identified three commonly
used Likert-type rating scales for evaluation: frequency (e.g., never,
sometimes, often, always), severity (e.g., not at all, a little, some, a lot),
and difficulty (e.g., not difficult, a little difficult, difficult, very
difficult). These three scales were therefore selected for comparison in this
present study.…”