Are contact lenses unsafe for kids and teens to wear?

Not necessarily: Contact lenses can be worn safely in children as long as they are handled appropriately, are cleaned regularly, and are removed as directed by an eye doctor. You should weigh the ability of your child (and you) to properly care for the lenses and the potential risk of infection against their discomfort and social stigma from wearing glasses when deciding whether to allow them to use contacts.

Depends: It really depends on the maturity level of the teen. Improper care, overwear, and poor hygiene can lead to permanent vision loss. I would only allow under very close supervision and would not allow extended wear(sleeping in lenses).