Adherence of a rigid gas permeable (RGP) contact lens to the cornea is an unsolved clinical problem in extended wear. This communication proposes that intraocular pressure (IOP) is a cofactor of this phenomenon. Intradiem fluctuations in the IOP can additionally stress the corneal epithelium and affect its biomechanical properties. The corneal surface is then susceptible to lens imprinting and eventual lens immobilization. The prevalence of lens adherence in the morning correlates with the early morning peak in IOP that is known to occur in many normotensive patients. The possibility arises that lens immobilization during sleep is causally related to the peak in IOP.