Table 5.

Rasch Indices for Each Unidimensional Domain Within Each Questionnaire, By Age Group

	Separation		Reliability		Mean person measure
	Person	Item	Person	Item
Child 5–11 years
Functional vision	1.55	2.86	0.71	0.89	1.47
Bothered by eyes / vision	1.33	3.07	0.64	0.90	1.67
Social	1.00	4.06	0.50	0.94	2.10
Frustration / Worry	1.27	3.19	0.62	0.91	1.56
Child 12–17 years
Functional vision	1.91	4.40	0.78	0.95	1.18
Bothered by eyes / vision	1.81	2.83	0.77	0.89	0.88
Social	1.43	2.04	0.67	0.81	1.88
Frustration / Worry	1.99	3.43	0.80	0.92	0.87
Proxy 0–4 years
Functional vision	2.11	4.30	0.82	0.95	1.73
Bothered by eyes / vision	1.81	3.92	0.77	0.94	3.08
Social	0.95	3.85	0.48	0.94	5.16
Proxy 5–11 years
Functional vision	2.39	4.06	0.85	0.94	1.49
Bothered by eyes / vision	1.91	4.84	0.78	0.96	3.34
Social	1.35	2.22	0.65	0.83	2.59
Frustration / Worry	1.15	2.16	0.57	0.82	3.22
Eye-care	1.40	2.48	0.66	0.86	1.32
Proxy 12–17 years
Functional vision	2.30	5.40	0.84	0.97	1.51
Bothered by eyes / vision	2.24	3.91	0.83	0.94	1.38
Social	1.97	3.78	0.79	0.93	2.84
Frustration / Worry	2.03	2.46	0.81	0.86	2.40
Eye-care	1.25	3.58	0.61	0.93	2.95
Parent
Impact on parent and family	1.27	4.99	0.62	0.96	3.20
Worry about child’s eye condition	2.27	6.64	0.84	0.98	0.15
Worry about self-perception / interactions	1.96	7.17	0.79	0.98	0.86
Worry about functional vision	2.02	8.70	0.80	0.99	1.70