An instrument used to examine internal health of the eye.


A medical doctor who has completed a residency program in ophthalmology and specializes in vision care that is related to medical conditions, such as treating diseases of the eye and performing ocular surgery. Title is M.D.


With reference to the eye and its functions.

OMA (Optical Manufacturers Association)

A trade organization for the manufacturers of ophthalmic frames and lenses.

OLA (Optical Laboratories Association)

A trade organization for wholesale laboratories.

Oculus Uterque (OU)

A term used by practitioners to refer to both eyes.

Oculus Sinister (OS)

A term used by practitioners to refer to the left eye.

Oculus Dexter (OD)

A term used by practitioners to refer to the right eye.


A device that excludes light from one or both eyes.


  1. An eyepiece.
  2. Pertaining to the eye.


The group of all eye care professionals who have contracted with the Claims Supervisor to provide Covered Service to Enrollees.


A condition that usually starts in childhood and stabilizes in the late teens or early twenties. Because the eye’s focusing powers are too strong for the size of the eye, near objects are seen more clearly and those far away appear blurry. Light is focused in front of the retina (see Myopia).

Near Point

The closest point at which accommodation can be momentarily maintained; also called punctum proximum (PP).


Nearsighted (difficulty seeing at distances).

Multifocal Lens

See Lens, Multifocal.

Mono Vision

A vision correction method where one eye is corrected for distance vision and the other is corrected for near vision.


Refers to only one eye or one side of a prism binocular.

Mirror Coating

A thin deposit of appropriate material to the front surface of a lens, causing a portion of the light striking the lens to reflect directly from the front surface.


The end user of products and services; the patient.

Major Reference Point

The point on a lens at which the specified distance prescription requirements shall apply (commonly but imprecisely referred to as the optical center).

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