This document defines common medical terms and abbreviations used in otolaryngology and optometry. It explains that a PE tube equalizes pressure between the middle ear and atmosphere and assists with fluid drainage. EENT refers to eyes, ears, nose and throat examinations. Bone conduction describes using skull bones to transmit sound waves for hearing. The abbreviation AU can refer to both ears together or each ear individually. OM is a middle ear infection commonly seen in children after upper respiratory infections. Additional terms defined include emmetropia, exotropia, OS for left eye, EOM for extraocular movement, and VA for visual acuity testing.

1. Peter Belford

2. Terms and Abbreviations
 Pressure Equalizing Tube – PE Tube
 Eye, Ear, Nose and Throat – EENT
 Bone Conduction – BC
 Both Ears – AU
 Otitis Media – OM
 Emmetropia – EM
 Exotropia – XT
 Left Eye - OS
 Extraocular Movement – EOM
 Visual Acuity - VA

3. PE Tube
 Equalize pressure between the middle
ear and the atmosphere.
 Assists in drainage of trapped fluid.

4. EENT
 Eyes, Ears, Nose, and Throat.

5. BC
 Using the bones of the skull to conduct
sound waves. Some hearing aids
employ this method and are almost as
effective as normal hearing.

6. Both Ears - AU
 Can either stand for both ears together:
Aures Unitas or each ear: Aures
Uterque.

7. OM
 Commonly found in children after an
upper respiratory infection. Referred to
as a middle ear infection. Pathogens
cause fluid to accumulate, could be
either watery (serous otitis media) or
pus (purulent otitis media).

8. EM

9. XT
 Outward turning of the eye. Also known
as wall-eyed. Cause by muscle
weakness.

10. OS
 Oculus Sinister or Left Eye. Not to be
confused with the late TLC member.

11. EOM
 Movement of the eye independent of the
skull.

12. VA
 Test of how well or poor someone sees.
May indicate a need for glasses. Often
performed using a Snellen Chart.

13. Peter Belford