The document defines medical terminology related to the special senses of the eye and ear. It provides definitions and abbreviations for terms including: - Pressure equalizing (PE) tubes, which are inserted into the eardrum to prevent fluid buildup behind it. - Eye, ear, nose, and throat (EENT), which refers to all of those areas unlike ENT which excludes the eyes. - Otitis media (OM), an ear infection of the middle ear that is more common in children and can be treated with antibiotics. - Emmetropia (EM), a relaxed state of the eye where it can focus on distant objects without effort.

1. Special Senses: Eye and Ear
By Ryan Atkins
Biology 120 – Medical Terminology
Module 13

2. Pressure Equalizing Tube
 Abbreviation: PE Tube
 Also called “ear tubes”, these devices are small cylinders that are surgically inserted into the
eardrum to prevent the accumulation of fluids behind the eardrum.
 Often the PE tubes will fall out on their own after approximately 6-12 months and require no
further intervention, but in some cases they may need to be surgically removed.

3. Eye, Ear, Nose, and Throat
 Abbreviation: EENT
 Easily confused with ENT, which stands for “Ear, Nose, and Throat” but excludes eyes.

4. Bone Conduction
 Abbreviation: BC
 Used to describe the conduction of sounds to the inner ear via the bones of the skull rather than
the eardrum.
 This technique can be used for individuals with hearing disabilities, although normally abled
individuals can also use bone conduction devices.

5. Both Ears
 Abbreviation: AU
 From Latin, auris utraque; literally “both ears”.

6. Otitis Media
 Abbreviation: OM
 Ot/o – Ear
 -itis – Inflammation
 Media – Middle
 An infection of the middle ear, more common in children than adults, that generally resolves itself
but can also be treated with antibiotics in severe cases or for individuals with otherwise weakened
or compromised immune systems.

7. Emmetropia
 Abbreviation: EM
 A relaxed state of the eye, in which the focus is on an object more than 6 meters away.
 The light rays entering the eye are roughly parallel and so they are focused on the retina without
any extra effort.

8. Exotropia
 Abbreviation: XT
 A form of strabismus (eye misalignment) in which one or both of the eyes are turned outward.
 The opposite of esotropia, or cross-eyed.
 Exotropia may be intermittent or constant, and can be observed in all age groups, genders, and
races.

9. Left Eye
 Abbreviation: OS
 From Latin, oculus sinister; literally “left eye”.

10. Extraocular Movement
 Abbreviation: EOM
 Regarding the six muscles of each eye controlled by cranial nerves III, IV, and VI which coordinate
the movement of the eyes.
 The six muscles are: superior rectus, inferior rectus, medial rectus, lateral rectus, superior oblique,
and inferior oblique.
 Additionally, the levator palpebrae superioris is responsible for retracting and elevating the eyelid.

11. Visual Acuity
 Abbreviation: VA
 The sharpness or clarity of vision.
 Visual acuity is most commonly tested by having a patient read a series of letters or numbers of
decreasing size from a fixed distance.
 “Perfect” visual acuity is most commonly referred to as 20/20 vision.