What happens when you wear contacts that have been overworn already?

[Torrey]

I'm wondering what happens when you wear contacts that have been overworn and needed to be thrown out as I am afraid I might have done with the contacts I had for a month.

[Tortilla Flat]

when we wear contacts, the secration from our eyes, dirt from outside will accumalate on the contact lenses and then become sediment . The sediment will accumalate more and more as the time we used contacts increases . In the later,the lenses will blur and make it uncomfortable to wear then we can't see clearly through them . Overworn contacts can cause infection on corneal and result in illness, so it is better to change your contacts regularly .

[Toston]

It is likely cause hurt to your eyes. I never worn overworn contacts. But I have experience of wearing overdue contact lenses. When i bought contacts, The seller told me that the contacts can be only worn for three month. But i forgot it and worn them over three months. Then, i felt eye dry, red eyes. Then, i visited an eye doctor, He told me that i shall give up the contacts and wear glasses. And i found my vision problems become more serious.