Sagittal depth considerations in the selection of the base curve radius of a soft contact lens.

Examination of the relationship between the sagittal depth of the cornea and the sagittal depth of an optimally fitting soft contact lens reveals that base curves are not always well chosen. The author reports a new system for selecting the number, range, and distribution of base curve radii such that the range of saggital depths clinically encountered is covered evenly. The saggital increment between adjacent base curves is then 0.1 mm.