Yes of course you can close your eyes with wearing contacts lenses. The eyes of people have to blink millions of times each day, so it is ok and a must to close your eyes when you are wearing contacts. However, you should not wear your contacts when you are sleeping whether at night or at noon. Some people do not take off their contacts when going to bad because they think it inconvenient and takes time to take the contacts off and then put them back on again. This is a very bad and harmful habit. If you are wearing congtacts when you are asleep, your eyes are closed, and will not blink, therefore, the secretion and circulation of tears decrease, leading to the tangible objects in the eyes' conjunctival sac easily depositing on the contacts, which worsens the oxygen deficit of cornea. If you usually wear contacts when you sleep, kompensatorisch will make new vessels grow around the cornea contributing cornea edema and epithele cells damaged, which is fatal to your eyes. Therefore, you should not wear your contacts when you are sleeping.