Once opened are astral senses able to be closed or deactivated at will such as through visualization? Compared to opening them how difficult is this to do? Once you start to hear and see spirits, will it be for life or if you don’t use your senses they will stop working eventually, and the chakras associated with astral senses, for example, the Brow Chakra (third eye) will close or deactivate?
They’re like anything else, they will atrophy without use. For example, if you stay in bed for months on end, you will lose the muscle mass in your thighs, and walking will then become difficult because you will not be able to support your body weight. Think of your spiritual senses as similar.
You chakras are never closed to begin with, so no. They will remain in the state they are in. It’s like riding a bike. Once you learn how, it doesn’t take very long to get back into the groove, no matter how long it has been since you last rode one.
If you wanted to shut yourself down, the easiest method would be just to ignore their input. The brain naturally shuts down what isn’t used.