| alpha angle | The angle between the visual and optic axes as they cross at the nodal point of the eye, the angle between the visual line and the major axis of the corneal ellipse. (05 Mar 2000) |
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| alveolar angle | The angle between the horizontal plane and a line connecting the base of the nasal spine and the middle point of the projection of the alveolus of the maxilla. (05 Mar 2000) |
| angle | 1. To fish with an angle (fishhook), or with hook and line. 2. <geometry> The figure made by two lines which meet. The difference of direction of two lines. In the lines meet, the point of meeting is the vertex of the angle. 3. A projecting or sharp corner; an angular fragment. "Though but an angle reached him of the stone." (Dryden) Curvilineal angle, one formed by two curved lines. External angles, angles formed by the sides of any right-lined figure, when the sides are produced or lengthened. Internal angles, those which are within any right-lined figure. Mixtilineal angle, one formed by a right line with a curved line. Oblique angle, one acute or obtuse, in opposition to a right angle. Obtuse angle, one greater than a right angle, or more than 90 deg . Rectilineal or Right-lined angle, one formed by two right lines. Right angle, one formed by a right line falling on another perpendicularly, or an angle of 90 deg (measured by a quarter circle). Solid angle, the figure formed by the meeting of three or more plane angles at one point. Spherical angle, one made by the meeting of two arcs of great circles, which mutually cut one another on the surface of a globe or sphere. Visual angle, the angle formed by two rays of light, or two straight lines drawn from the extreme points of an object to the center of the eye. 4. <astronomy> A name given to four of the twelve astrological houses. Origin: F. Angle, L. Angulus angle, corner; akin to uncus hook, Gr. Bent, crooked, angular, a bend or hollow, AS. Angel hook, fish-hook, G. Angel, and F. Anchor. (16 Mar 1998) |
| angle closure glaucoma | <ophthalmology> Primary glaucoma in which contact of the iris with the peripheral cornea excludes aqueous humor from the trabecular drainage meshwork causing a sudden blockage of the normal fluid circulation within the eyeball resulting in increased intraocular pressure. Increased pressure within the eyeball can cause damage to the optic nerve and blindness. Symptoms include severe eye or facial pain, nausea, vomiting, decreased vision, blurred vision and seeing halos around objects. The eye appears red with a steamy cornea and a fixed (nonreactive) dilated pupil. Treatment is emergent with medications to lower the pressure within the eye. Synonym: acute glaucoma, closed-angle glaucoma, narrow-angle glaucoma. (14 Aug 2000) |
| Angle, Edward | <person> U.S. Orthodontist, 1855-1930. See: Angle's classification of malocclusion. (05 Mar 2000) |
| angle of anomaly | <ophthalmology> An obsolete term for the degree of deviation from parallelism of the visual axes of the eyes. (05 Mar 2000) |
| angle of antetorsion | <orthopaedics> The angle formed by a line drawn through the centre of the long axis of the neck of the femur meeting a line drawn in the transverse axis of the condyles, when the bone is viewed from above, looking straight down through the head of the femur. It is used to illustrate the normal degree of anteversion about 12 |
| angle of anteversion | <orthopaedics> The angle formed by a line drawn through the centre of the long axis of the neck of the femur meeting a line drawn in the transverse axis of the condyles, when the bone is viewed from above, looking straight down through the head of the femur. It is used to illustrate the normal degree of anteversion about 12 |
| angle of aperture | <ophthalmology, optics> The angle formed by lines drawn from the ends of the diameter of a lens to its point of focus. See: angular aperture. (05 Mar 2000) |
| angle of convergence | <optics> The angle that the visual axis makes with the median line when a near object is viewed. (05 Mar 2000) |
| angle of declination | An obsolete term for angle of anteversion. (05 Mar 2000) |
| angle of depression | <orthopaedics> The angle formed by the meeting of a line drawn through the shaft of the femur with one passing through the long axis of the femoral neck; normally it is about 127 |
| angle of deviation | <optics> In a prism, the sum of the angle's of incidence and emergence minus the apical angle of a prism, in optics, angle of refraction, in strabismus, angle of anomaly. (05 Mar 2000) |
| angle of eccentricity | <ophthalmology> In strabismus, the angle between the line of fixation and the line of normal foveal fixation. (05 Mar 2000) |
| angle of emergence | <optics> The angle formed by a light ray emerging from the second surface of a prism and a line parallel to the incident ray. Compare: angle of deviation. (05 Mar 2000) |