Why are extended wear contact lenses (sleeping while wearing contact lenses) unhealthy for my eyes?
This mode of wearing contact lenses is unhealthy for several reasons. First, the cornea only gets oxygen from the air; there is no blood supply or other circulation. While wearing contact lenses, the corneas oxygen exposure is significantly reduced. “Overwear” starves the cornea of oxygen and goes into a state of oxygen deprivation called hypoxia. This signals blood vessels from the white part of the eye (sclera) to grow into the cornea. This neovascularization, or new blood vessel growth, is an attempt to provide an alternative method of nurishing the corneal tissue. Unfortunately, these blood vessels are not transparent and blindness can occur if one of the blood vessels grow across the center of the pupil. Next, dirt and deposits on the lenses build rapidly. When the lenses are not removed to be cleaned, rinsed and disinfected, the protein and lipid coating thickens to an unacceptable level. The health of the cornea is further is jeopardized as oxygen is now diminished, and the dirt
