Effect Of Lid Position, Corneal Diameter, Corneal Shape, And Rigid Lens Overall Diameter On Lens Movement And Positioning.

The purpose of the study was to determine the normal position of the lid margins with respect to the limbus of the general population. The lid positions were then correlated to the
positioning of different diameter rigid lenses. In the fitting and design of rigid contact lenses it is important to know the characteristics, and the variation in these characteristics, that affect lens positioning and comfort. One of the most important factors is lid position with respect to
the limbus and the effect of the lid forces on lens position. Very little quantitative data is available on the lid position with respect to the corneal limbus and in turn the effect of
the lid position on lens positioning and movement. This information is important in designing lenses and in fitting. With such information one can better determine what lens diameters
should be used to best fit the majority of the population and what increment in lens diameter is significant in changing lens performance.