Corneal Thickness Changes Associated with Daily and Extended Contact Lens Wear

Human corneal thickness was measured during daily wear of hydrogel contact lenses and then during the initial 2 weeks extended wear of hyper‐thin (0.035 mm), low water content (38.6%), hydrogel lenses (polymacon). Results show that subjects wearing standard thickness (0.12 mm) and ultra‐thin (0.07 mm) hydrogel lenses of low water content for daily wear will exhibit a diurnal swelling of the cornea. Subjects wearing hyper‐thin (0.035 mm) low minus power hydrogel contact lenses of low water content for extended wear will exhibit overnight (closed eye) swelling of the cornea followed by a deswelling throughout the day (open eye). The degree of swelling and deswelling can vary greatly among individual subjects.