This document defines and describes several medical terms related to the eyes, ears, and throat. It defines pressure equalizing tube, otitis media, emmetropia, exotropia, extraocular movement, and visual acuity. Pressure equalizing tubes relieve problems in the middle ear. Otitis media is the second most common childhood disease. Emmetropia is a state of proper eye alignment. Exotropia is crossed eyes. Extraocular movement tests eye muscle function. Visual acuity measures clarity of vision.

1. CHAPTER 13
Ariuntungalag Otgonbayar

2. Pressure equalizing tube - PE tube
• A small cylindric device placed through an incision in the tympanic
membrane to relieve problems of the middle ear, such as fluid
accumulation or auris media infection caused by eustachian tube
dysfunction.

3. Eye, ear, nose and throat - EENT

4. Bone conduction - BC
• The process by which sound waves are transmitted to the inner ear
by the cranial bones without traveling through the air in the ear
canal

5. Both ears - AU

6. Otitis media - OM
• The second most common disease of childhood, after upper
respiratory infection (URI). OM is also the most common cause for
childhood visits to a physician's office.

7. Emmetropia - EM
• A state of proper correlation between the refractive system of the
eye and the axial length of the eyeball, rays of light entering the eye
parallel to the optic axis being brought to focus exactly on the
retina.

8. Exotropia - XT
• A disorder in which the two eyes do not line up in the same
direction, and therefore do not look at the same object at the same
time. The condition is more commonly known as "crossed eyes."

9. Left eye - OS

10. Extraocular movement - EOM
• An examination of the function of the eye muscles. A doctor
observes the movement of the eyes in six specific directions.

11. Visual acuity - VA
• Acuteness or clearness of vision, which is dependent on the
sharpness of the retinal focus within the eye and the sensitivity of
the interpretative faculty of the brain.
Visual acuity tests