Axial length of the emmetropic eye and its relation to the head size.

The results of the ultrasonographic measurements of the ocular components in 40 emmetropic eyes from men of nearly the same age are presented and the possible relation between the axial eye length and the head size is discussed. A significant correlation was found between the axial eye length and the head circumference (P less than 0.001), between the axial eye length and the head length (P less than 0.01) and between the axial eye length and the head breadth (P less than 0.02). A significant correlation was also found between the axial eye length and the height of the subjects (P less than 0.01). It is suggested that such a correlation can explain not only the wide individual range of axial eye lengths in emmetropic eyes, but also the existing difference in axial eye length between the sexes. The mean eye length was 23.82 mm in 40 men and 23.02 mm in 10 women; both sexes were of the same age (20-30 years).