It can be dangerous to sleep in contacts. If you sleep in contacts accidently, you can apply some artificial tears to flush your eyes. Besides, you need to drink more water. This can help lubricate your eyes and relieve red and dry eye symptoms. If you can't take off your contacts immediately, you must calm down and drink more water and flush your eyes with artificial tears again and again. You can take off the contacts easily after your eyes can produce enough water. Don't try to take off contacts by force because that will cause great damages.