No, you cannot sleep in your contact lenses. Although some people will tell you they sleep in them all the time without problems, this is irrelevant.
Don't let laziness risk going blind.
Your eyes need to breath. Wearing contact lenses reduces oxygen to your eyes, and wearing them too long will starve your eyes of oxygen for too long of time. Sleeping in them is dangerous. Don't do it. Contact lenses also need to be re-hydrated, rinsed and disinfected, you can't do that while their in your eyes so you need to remove them!
We know many people who sleep in their contact lenses, and have done so many, many times without problems.
We know many people who slept in their contact lenses, and were rushed to the Emergency Room, went blind or had permanent vision impairment etc.
Which will you be? Sleeping with your contact lenses on simply increases your risk of harm, it could take just 1 nights sleep to go bling.
Again... Don't be lazy.