TABLE 4.

Correlation of age and central nucleus width

Age group	No of patients	Mean width	S.D.
< 40 yrs.	18	2.39 mm	0.21
41-50 yrs.	77	2.63 mm	0.28
51-60 yrs.	143	2.80 mm	0.23
61-70 yrs.	130	2.98 mm	0.25
> 71 yrs.	61	3.29 mm	0.60

Analysis of variation
Variation	SS	DF	MS	F Statistic	P value
Between	21.48	4	5.37	51.71	< 0.001
Within	44.04	424	0.10
Total	65.53	428