It’s called an otoscope, and your doctor uses it to get a better view, especially if you have trouble hearing or your ear hurts. After all, it’s tight quarters in there. And dark, too. With it, your doctor can see an irritated eardrum, a swollen ear canal, fluid that’s a sign of infection, extra wax that may be causing trouble, and other problems. They may also be able to tell if you have pressure issues by using it to send a little puff of air into the canal.