Contact lenses that change your eye color and make a fashion statement are very popular now. Some doctors do not like to recommend them.
Like anything else if you follow safe guidelines you will be ok. I am not a fan of motorcycles and I would not ride one but they are safe when used properly. Wild and crazy contact lenses are okay also but you would never see me wearing them.
The problem is that many people do not use common sense whether it is wearing contacts or riding motorcycles. If you get your regular eye exam and make sure your eyes are healthy it is ok to wear colored and decorative contacts. Children certainly need to have the permission of their parent. These contacts are not to be worn when you are sleeping. If your eye hurts with the contact in, do not wear them because something is wrong. All of this is common sense but unfortunately people who do not use common sense get into problems all the time.
Blindness can result from improper use of contacts. If you have a red eye from a contact then take it out immediately and go see you eye doctor. I have seen some wild and crazy contacts and they are popular among teenagers and some adults. Buying them online is also popular and I am not sure all companies follow the FDA guidelines.
If you common sense and see your eye doctor, you can enjoy those wild and crazy contact lenses.
I am a Board Certified Ophthalmologist who has been in practice for 30 years.