Are eye infections common when wearing contact lenses? How can this be prevented?

Yes. Yes, especially if you sleep in your contacts. Always remove your contacts before going to sleep. Clean them everyday.
Yes. This is why it is imperative to wash hands well before handling contacts.

Related Questions

Why do contact lens wearers get more eye infections?

Eye hygiene. Practice good eye hygiene. Do not unnecessarily touch your eyes. Always wash your hands with soap when inserting or removing contacts. Clean your contacts with a product & a schedule recommended by the manufacturer & your doctor. Do not use them if damaged or dirty. Replace as recommended. Don't use them except as directed (e.g. Don't wear them overnight if not designed for that purpose). Read more...
Contacts. When a contact lens is worn, the eye is not getting as much ocygen. This low oxygen state is a perfect incubator for certain bacteria, such as pseudomonas. The bacteria grow close to the eye and are much more likely to penetrate the eye and hence, cause infection. Do not sleep in your contact lenses, since this makes infection even more likely. Read more...
Yes . Yes , but not many more. Contact lenses taken care of correctly still come with a risk of eye infection. Whenever you put a foreign object on the surface of the eye you place the eye at risk. Following appropriate disinfection regimes should allow you to wear contacts without any problem. If you get a red eye while wearing a contact lens-- take the lens out immediately and call your M.D. Read more...