Depends if they are dirty or not. Whenever you want.
Piggy takes off his glasses to clean them three times in the book "Lord of the Flies" by William Golding.
8 glasses of water a
you should clean your years at least twice a day
none
It depends on how dirty it is or how clean you want it to be. It also depend on how much time in a year you can spend to clean your deck. You can clean it as many times as you want though.
There is no particular number of times you should clean your horse. It still should be done regularly. You should make sure to check for cuts or other injuries.
Try soaking the glasses in white vinegar to remove any hard water deposits. Unfortunately, many times this streaking is a quality of the type and age of the glass itself and cannot be changed.
At least once a year open it up and clean out all the dust.
3 time a day
3or 4
it's no how many times it how much some say a litre a day and others say 8 glasses a day -ninja style exit-
You should only clean your piercings 3-5 times a day. NEVER more then 5 times since its just as bad as not cleaning it at all. ...why didn't you jsut ask your piercer?