op-, opt-, optico-, opsi-, opso-, -opia, -ops, -opsia, -opsis, -opsy, -optic, -opic, -opy

An image of external objects fixed on the retina by the photochemical action of light on the visual purple.

1. The production of an optogram on the retina by the photochemical action of light on the visual purple.
2. The fixation of an image in the eye.

Referring to movements of the eyes.

An instrument for measuring the distance of distinct vision, mainly for the selection of eve glasses.

A health care professional who is licensed to provide primary eye care services:

1. To examine and diagnose eye diseases such as glaucoma, cataracts, and retinal diseases and, in certain states in the U.S., to treat them.
2. To diagnose related systemic (bodywide) conditions such as hypertension and diabetes that may affect the eyes.
3. To examine, to diagnose, and to treat visual conditions; such as, nearsightedness, farsightedness, astigmatism, and presbyopia.
4. To prescribe glasses, contact lenses, low vision rehabilitation, and medications; as well as, to perform minor surgical procedures; such as, the removal of foreign bodies.

1. The professional practice of primary eye and vision care that includes the measurement of visual refractive power and the correction of visual defects with lenses or glasses.
2. The practice of non-medical eye care, dealing primarily with the testing of vision for refractive errors and with the prescription and fitting of corrective lenses.
3. The professional practice of eye and vision care for the diagnosis, treatment, and prevention of diseases and conditions of the eyes and visual systems.
4. The practice of examining eyes in order to determine levels of vision and then prescribing and supplying any necessary corrective lenses.

A device for measuring eye muscle balance and vergence (inward or outward turning of both eyes when they are focusing on an object).

An instrument to enable one to hear the murmur of muscular contractions.

The technology of optical instruments and apparatus.

1. The style of type used on an eye chart.
2. A standardized symbol for testing vision.
3. Types used to determine visual acuity when different sizes are presented to a person and the smallest size the person can reliably identify determines the person's level of achievement.

A condition of normal vision and alignment of the eyes.

1. A condition in which the visual image is seen to move rapidly from side to side or vertically.
2. The subjective sensation of oscillation of objects viewed.

Abnormal acuteness, or sharpness, of sight: Oxyopia is an unusually keen and highly developed vision which arises from an increased suseptibility of the retina.

In medicine, the pathologic continuance or recurrence of a visual sensation after the stimulus is gone: A palinopsia involves the abnormal repetitions of visual hallucinations.

1. Including everything visible in one view.
2. Permitting the viewing of all parts or elements.