Table 4.

Age standardised prevalence of poor vision, and causal disorders, in three distinct socioeconomic groups, north London. Group 3 comprises residents of the most underprivileged areas (Jarman score 36.06); group 2, residents of areas with intermediate scores (33.98, 18.51, and 21.35); and group 1, residents of the least underprivileged areas (scores −0.88 and 0.35). The age structure of the whole sample was used as the standard

Condition (in one or both eyes)	No (age standardised %) in socioeconomic group				P values for comparison of groups*
	1 (n=757)	2 (n=203)	3 (n=587)		1 v 2	1 v 3	2 v 3
Visual impairment or blindness:
Visual acuity <6/12 in one or both eyes	354 (45)	104 (55)	357 (61)		0.039	0.016	0.046
Visual acuity <6/12 in both eyes	164 (20)	60 (34)	224 (39)		0.005	0.002	0.007
Main contributing conditions:
Refractive error causing visual impairment	43 (6)	18 (8)	75 (12)		0.016	0.011	0.005
Cataract causing visual impairment	181 (23)	69 (38)	201 (35)		0.004	0.032	0.767
Age related macular disease	81 (10)	10 (6)	42 (8)		0.013	0.299	0.426

^*From logistic regressions taking into account the cluster sampling design effect.