 The most prominent risks associated with long-term, chronic low oxygen to the cornea include corneal neovascularization, increased epithelial permeability, bacterial adherence, microcysts, corneal edema, endothelial polymegethism, dry eye and potential increase in myopia.That is why much of the research into the latest soft and rigid contact lens materials has centered on improving oxygen transmission through the lens.Mishandling of contact lenses can also cause problems.