Table 3. Fit Statistics using Rasch Analysis with respective Items and Subscales from National Eye Institute Visual Function Questionnaire (NEI VFQ-25).

Questions	Items	Subscales	Measure	Infit MNSQ	Outfit MNSQ
Q1	General health	General health	0.03	0.98	1.28
Q2	General vision	General vision	0.02	0.62	0.77
Q3	Worry about eyesight	Mental health	0.05	1.20	1.24
Q4	Pain around eyes	Ocular pain	-0.02	1.58	2.03
Q5	Reading normal newsprint	Near vision	0.03	0.93	0.93
Q6	Seeing well up close	Near vision	0.01	0.88	0.83
Q7	Finding objects on crowded shelf	Near vision	-0.01	0.79	0.73
Q8	Street signs	Distance vision	0.01	0.91	0.92
Q9	Going downstairs at night	Distance vision	0.00	0.79	0.75
Q10	Seeing objects off to side	Peripheral vision	-0.01	0.72	0.71
Q11	Seeing how people react	Social function	-0.04	0.90	0.61
Q12	Matching clothes	Color vision	-0.04	0.85	0.84
Q13	Visiting others	Social function	-0.02	1.07	0.87
Q14	Going out to movies/plays	Distance vision	0.00	1.19	1.24
Q17	Accomplish less	Role limitations	0.01	1.40	1.41
Q18	Limited endurance	Role limitations	0.01	0.88	0.83
Q19	Amount of time in pain	Ocular pain	0.00	1.65	1.75
Q20	Stay home most of the time	Dependency	-0.01	0.89	0.83
Q21	Frustrated	Mental health	0.01	1.06	1.02
Q22	No control	Mental health	0.00	1.01	0.92
Q23	Rely too much on others’ words	Dependency	-0.02	1.07	0.87
Q24	Need much help from others	Dependency	-0.01	0.96	0.87
Q25	Embarrassment	Mental health	-0.02	1.30	0.99

MNSQ: mean square