Table 3. Analysis of variance with the number of consecutive tests showing blindness in a test location (N) and the definition of ‘perimetrically blind’ (B) as within-subject factors and the persistence of blindness as dependent variable.

	df	MS	dfe	MSe	F	P
mean	1	680.65	52	0.08460	8045	<0.001
N	3	0.47354	156	0.00702	67	<0.001
B	3	0.57498	156	0.01089	53	<0.001
N*B	9	0.00547	468	0.00161	3	<0.001

df  =  degrees of freedom; MS = mean squares (MS = SS/df with SS = sum of squares); dfe is df for error; MSe = mean squares for error.