Table 3.

Correlation between data of Experiment 3 and data of Experiments 1 and 2.

	Experiment 1				Experiment 2
	Far	Mid	Near	Overall	Far	Mid	Near	Overall
Correlation between Percival’s criterion and discomfort score
Q1: Eye tiredness	0.278	0.406	0.280	0.296	0.549	0.219	0.168	0.344
Q2: Vision clarity	−0.045	−0.102	−0.124	−0.083	0.181	−0.075	−0.184	0.006
Q3: Neck and back	0.063	0.323	0.300	0.222	0.172	−0.039	0.128	0.076
Q4: Eyestrain	0.169	0.415	0.299	0.272	0.420	0.077	0.205	0.260
Q5: Headache	0.248	0.446	0.098	0.252	0.138	0.062	0.197	0.147
Correlation between Sheard’s criterion and discomfort score
Q1: Eye tiredness	0.118	0.350	0.271	0.238	0.327	0.233	0.089	0.257
Q2: Vision clarity	0.210	0.273	0.334	0.271	0.207	−0.052	0.052	0.092
Q3: Neck and back	−0.134	0.033	0.289	0.053	0.152	−0.129	0.227	0.078
Q4: Eyestrain	0.197	0.251	0.318	0.247	0.410	0.021	0.172	0.229
Q5: Headache	0.136	0.283	0.105	0.174	0.138	0.035	0.342	0.175
Correlation between the distance to phoria and discomfort score
Q1: Eye tiredness	0.169	0.318	0.276	0.275	−0.092	0.308	0.220	0.118
Q2: Vision clarity	0.036	0.172	0.436	0.208	−0.167	−0.111	0.120	−0.054
Q3: Neck and back	0.023	−0.019	0.307	0.102	−0.038	−0.032	0.351	0.130
Q4: Eyestrain	0.070	0.175	0.340	0.210	0.120	0.073	0.248	0.108
Q5: Headache	0.050	0.272	0.244	0.215	−0.107	0.133	0.518	0.153