Originally Posted by Englishteacher1

If you go past 30 days, there are many things that can go wrong, including an infection from an overused contact lens becoming contaminated. Here's what I found on a website from the University of Iowa:

"Contact Lens Overwear . . . occurs when the contact is worn longer than the cornea can tolerate. Not enough oxygen gets to the cornea resulting in temporary discomfort and blurred vision. The treatment is to discontinue wearing the contact lenses for a few days."

Further on: "Corneal abrasion . . . is a "scratch" on the surface of the cornea resulting from a poorly-fitting contact lens, foreign material under the contact lens or overwear. The treatments include antibiotics and possible patching of the eye. Infection may result from this condition."

Finally: "Corneal ulcer . . . is the most severe complication of contact lenses and is more often seen with extended wear soft lenses. In this condition, trauma or contamination to the cornea from the contact lens results in an infection. This sometimes requires hospitalization for treatment and can lead to extensive corneal scarring. Corneal transplant surgery may be required to regain good vision. Although very rare, it is possible that a patient could lose an eye from a severe corneal ulcer." http://www.uihealthcare.com/depts/med/ophthalmology/contactlens/handlinglenses/complications.html