Contact lenses are meant to be worn every day, how long you wear them each day is the question. The doctor will tell you how long you can just wear them. The usual recommendation is from 8-15 hours every day.
There are also some aspects that need to be considered just like when you feel that your eye is becoming sensitive or dry. This means that you need to take a break. So give your eyes some rest for one to two hours. Clean them and store them in the case. If in case this usually happens, then check it with your doctor. There are now lenses meant for those people who have dry eyes.
Experts also advised that your remove lenses an hour before sleeping to help the eyes recuperate before sleeping.