A small dot of India ink has been applied to the surface of this right tympanic membrane in order to demonstrate the natural self cleansing properties of the surface of the tympanic membrane. This phenomenon is referred to as "migration". This Hopkins Rod Tele-otoscope photograph was taken one week after the ink was applied. Notice how the peripheral circumference of the ink has broken up and is spreading out circumferentially over the surface of the tympanic membrane.