Article ID Journal Published Year Pages File Type
9075379 Contact Lens and Anterior Eye 2005 5 Pages PDF
Abstract
The removal of rigid contact lenses from the eye, using the eyelids, is a relatively simple procedure. However, there is a sequence of biomechanical events underlying this procedure which are not well understood. By using high-speed videokeratoscopy (50 Hz), we have shown that during the lid-pull procedure the cornea typically shows a significant increase in with-the-rule astigmatism by an average of 2.19 D (axial power). The average increase in steep K power was 1.22 D (S.D. ±1.05 D) and the average decrease in flat K power was 0.97 D (S.D. ±1.05 D). This change in corneal topography increases the edge lift of the lens at 12 and 6 O'clock locations of the lens, enhancing the removal process. When the subject blinks, as the lid margins reach the lens edge, the lens flexes and the eye retracts by an average of 0.66 mm (S.D. ±0.27 mm). This retraction again enhances the act of lens removal.
Related Topics
Health Sciences Medicine and Dentistry Ophthalmology
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