This is an example of what happens when people over wear their contact lenses. The cornea is the only structure in the body that gets it’s oxygen directly from the air. When we wear contact lenses, unless we have enough waking hours of not wearing the lenses, the cornea becomes starved from oxygen. Blood vessels start to grow into the cornea to feed the starved cells. Over time the health of the cornea becomes compromised, leading to inflammations and vision-threatening infections that can cause permanent loss of vision.