visual axis

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Related to visual axis: fovea, pupillary axis


 [ak´sis] (pl. ax´es)
1. a line through a center of a body, or about which a structure revolves.
the second cervical vertebra. adj., adj ax´ial.
2. the position of the cylindrical part of a lens, used for correcting astigmatism; the range of values is from 0° to 180°.
celiac axis celiac trunk.
dorsoventral axis one passing from the posterior to the anterior surface of the body.
electrical axis of heart the preponderant direction of current flow through the heart, a consequence of the electromotive forces within the heart. It may be computed on either an instantaneous basis or a mean basis.
frontal axis an imaginary line running from right to left through the center of the eyeball.
axis of heart a line passing through the center of the base of the heart to the apex.
instantaneous electrical axis the electrical axis of the heart determined at a given point in time.
lead axis the imaginary direct line between the two electrodes of the bipolar leads or between the positive electrode and the reference point of the unipolar leads.
mean electrical axis the average direction of the activation or repolarization process during the cardiac cycle; it may be determined for any deflection (P, QRS, ST-T) and in the frontal, transverse, or sagittal plane.
optic axis
1. a line connecting the center of the anterior curvature of the cornea (anterior pole) with that of the posterior curvature of the sclera (posterior pole).
2. the hypothetical straight line passing through the centers of curvature of the front and back surfaces of a simple lens.
phlebostatic axis a point located by drawing an imaginary line from the fourth intercostal space at the sternum and finding its intersection with an imaginary line drawn down the center of the chest below the axillae.
Phlebostatic axis.
sagittal axis an imaginary line extending through the anterior and posterior poles of the eye.
visual axis an imaginary line passing from the midpoint of the visual field to the fovea centralis.
Axes of the eye. From Dorland's , 2000.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

vis·u·al ax·is

the straight line extending from the object seen, through the center of the pupil, to the macula lutea of the retina.
Synonym(s): line of vision
Farlex Partner Medical Dictionary © Farlex 2012

vis·u·al a·xis

(vizh'ū-ăl ak'sis)
The straight line extending from the object seen, through the center of the pupil, to the macula lutea of the retina.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
This may be because VAO was described as a fibrosis of anterior or posterior capsular opening and opacification of anterior vitreous surface that closed or threated the optic visual axis in this study.
Effectivity was defined as the ability of the ptosis crutch to effectively elevate the upper eyelid to clear the visual axis. The ptosis crutch was successful in elevating the eyelid to clear the visual axis.
Visual fields were produced using the visual axis as a central point, around which the angle of the visual arc was plotted.
Construct a sculpture by arranging smaller forms around the visual axis in different positions so that their combined "weight" equals that of larger masses, thus creating the feeling of.balance.
If the ulcer is small in size and located away from the visual axis, the long term effects are likely to be less severe than if it is located over the pupil on the visual axis, as the resulting scarring is likely to obscure their vision and result in glare and reduced visual acuity.
Ensuring a clear visual axis after pediatric cataract surgery is crucial for good visual acuity results.
Other major post operative complications such as inflammatory membrane, irregular pupil, posterior/anterior syneache and opacification of visual axis were not seen during follow up period.
Grade II PCO is present in the central visual axis, detectable in an undilated pupil.
At far convergence distances, where the visual axes (the visual axis is the line containing the point on which the eye is fixating, the optical nodal point of the eye, and the center of the fovea (Howard, 2012); a visual line is any straight line passing through the pupil and optical nodal point joining a distal object and a unique location on the retina) are nearly parallel (i.e., the eyes are converged at infinity), the vergence innervation is negligible relative to the version innervation.
Glasses or contact lenses that correct the defocus on the main visual axis can create a slight degree of farsightedness in the peripheral retina, David Troilo at SUNY College of Optometry in New York City explained.
The visual function is stricken, in fore rank, because the visual analyzer is a sensory system, but and because of this orientation after a visual axis, carry temporally the vibration is earnest affected (ISO 2631-1, 1997).

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