BIFOCAL CONTROL OF MYOPIA
Tables of Results

Means (M), Medians (Mdn), Standard Deviations (SD) and t-tests with degrees of freedom (df) and levels of confidence (LC) for the ending age, beginning refraction and annual rate of progression for the right (OD) and left (OS) eyes of combined Native American and Caucasian bifocal and control groups (all refractive errors in diopters - D).

Group, Age Number and df	Measure	Ending Age	Beginning Rx (D)		Annual Rates (D)
			OD	OS	OD	OS
bifocal age 6-8 N = 16	M	11.81	-0.41	-0.33	0.06	0.04
	Mdn	11.00	-0.19	-0.25	-0.03	-0.04
	SD	3.50	0.89	0.86	0.30	0.25
control age 6-8 N = 74	M	11.59	-0.45	-0.41	-0.61	-0.57
	Mdn	11.00	-0.62	-0.56	-0.55	-0.50
	SD	3.01	1.11	1.13	0.46	0.45
df =88	t	0.227	0.155	0.331	7.142	7.310
	LC	insig.	insig.	insig.	0.001	0.001
bifocal age 9 N = 17	M	13.18	-1.05	-1.02	-0.03	0.00
	Mdn	14.00	-1.25	-1.25	-0.06	-0.06
	SD	2.12	1.16	1.22	0.21	0.22
control age 9 N = 53	M	13.09	-1.04	-1.06	-0.53	-0.53
	Mdn	12.00	-1.25	-1.25	-0.44	-0.48
	SD	2.80	1.08	1.12	0.38	0.35
df = 68	t	0.156	0.040	0.108	6.738	7.063
	LC	insig.	inslg.	insig.	0.001	0.001
bifocal age 10 N = 30	M	13.77	-0.70	-0.70	-0.07	-0.05
	Mdn	14.00	-0.56	-0.69	-0.06	-0.06
	SD	1.91	1.58	1.81	0.16	0.17
control age 10 N = 59	M	13.63	-1.29	-1.16	-0.56	-0.55
	Mdn	13.00	-1.37	-1.25	-0.48	-0.48
	SD	2.34	0.97	1.18	0.38	0.35
df = 87	t	0.298	1.849	1.236	8.479	9.202
	LC	insig.	insig.	insig.	0.001	0.001
bifocal age 11 N = 32	M	14.41	-1.53	-1.55	-0.05	-0.08
	Mdn	14.00	-1.12	-1.25	-0.09	-0.11
	SD	1.78	1.44	1.54	0.23	0.20
control age 11 N = 63	M	14.83	-1.60	-1.45	-0.52	-0.54
	Mdn	14.00	-1.62	-1.62	-0.44	-0.46
	SD	2.89	0.98	1.14	0.33	0.35
df = 92	t	0.863	0.230	0.311	7.957	7.985
	LC	insig.	insig.	insig.	0.001	0.001
bifocal age 12 N = 35	M	15.60	-1.85	-1.80	-0.07	-0.09
	Mdn	16.00	-1.37	-1.50	-0.09	-0.08
	SD	1.94	1.79	1.70	0.15	0.18
control age 12 N = 78	M	14.77	-1.67	-1.62	-0.56	-0.53
	Mdn	14.00	-1.50	-1.44	-0.49	0.43
	SD	1.74	1.43	1.53	0.43	0.38
df = 111	t	2.143	0.511	0.537	8.825	8.129
	LC	0.05	insig.	insig.	0.001	0.001
bifocal age 13 N = 50	M	16.70	-1.69	-1.65	-0.09	-0.08
	Mdn	17.00	-1.25	-1.37	-0.06	-0.06
	SD	1.64	1.51	1.52	0.17	0.16
control age 13 N = 53	M	15.96	-1.80	-1.70	-0.42	-0.40
	Mdn	15.00	-1.75	-1.62	-0.37	-0.37
	SD	1.77	1.21	1.27	0.32	0.32
df = 101	t	2.181	0.383	0.171	6.378	6.296
	LC	0.05	insig.	insig.	0.001	0.001
bifocal age 14 N = 21	M	17.24	-1.87	-1.88	-0.01	-0.02
	Mdn	17.00	-1.37	-1.25	-0.06	-0.06
	SD	1.51	1.46	1.47	0.13	0.20
control age 14 N = 40	M	16.47	-2.16	-2.08	-0.42	-0.41
	Mdn	16.00	-2.37	-2.13	-0.32	-0.31
	SD	1.58	1.59	1.60	0.39	0.33
df =59	t	3.444	0.704	0.495	5.904	5.541
	LC	0.01	insig.	insig.	0.001	0.001
bifocal age 15 N = 40	M	18.13	-2.33	-2.33	-0.01	-0.02
	Mdn	18.00	-2.06	-2.19	-0.04	-0.04
	SD	1.63	1.45	1.58	0.19	0.16
control age 15 N = 39	M	17.74	-2.14	-1.99	-0.35	-0.33
	Mdn	18.00	-2.00	-1.75	-0.25	-0.31
	SD	1.63	1.67	1.52	0.32	0.30
df = 77	t	1.050	0.549	0.948	5.632	5.756
	LC	insig.	insig.	insig.	0.001	0.001
bifocal age 16 N = 18	M	18.56	-2.52	-2.38	0.04	0.02
	Mdn	18.50	-2.12	-1.63	0.00	-0.02
	SD	1.50	1.78	1.65	0.24	0.16
control age 16 N = 19	M	18.32	-2.21	-2.31	-0.39	-0.34
	Mdn	18.00	-1.62	-1.75	-0.32	-0.31
	SD	1.03	1.59	1.64	0.30	0.18
df = 35	t	0.549	1.081	0.116	4.720	6.128
	LC	insig.	insig.	insig.	0.001	0.001