Viewing aids are tools used to help people see objects more clearly. A LOUPE is a small magnifying glass that is held in the hand and used to examine small objects. It is often used by jewelers, watchmakers, and photographers. A periscope is an instrument used to view objects from a distance or around corners. It consists of two mirrors set at an angle so that an observer can look through them and see an image of an object that is not directly visible.