line(redirected from lines of sight)
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See also: linea.
See also: linea.
lineClinical medicine A popular term for an IV catheter Drug slang An elongated trail of relatively pure pulverized cocaine, usually snorted through a straw Telemedicine A telecommunication wire or other conduit. See Copper line, Digital subscriber line, Hotline, Medline, Leased line, T-1 line, T-3 line Vox populi A 2-D streak or mark or strip. See Bottom line, E-1 line, Fine line, Frankfort (horizontal) line, Gatekeeper guideline, Harvard guideline, Iliopectineal line, Intertrochanteric line, Lead line, Marionette line, Midclavicular line, Ohngren's line, Regression line, Skinner's line, Squamocolumnar Z line.
Synonym(s): linea [TA] .
linea subpopulation with certain characteristics in common. Thus a population of insects might be divided into several lines, depending on their tolerance to insecticides, and each line may be further inbred.
base line The line joining the centres of rotation of the two eyes. It is approximately equal to the interpupillary distance (Fig. L20). See interocular distance.
demand line The line in Donders' diagram that represents the perfect amount of convergence required for each level of accommodation, for single binocular vision. Syn. orthophoria line; Donders' line.
line of direction Line joining an object in space with its image on the retina (allowing for the optical properties of the eye). The line joining the fixation point to the fovea is called the principal line of direction. However, the object appears to lie along a visual direction and that direction in visual space associated with the fovea is called the principal visual direction. All other visual directions associated with other retinal points are called secondary visual directions. The principal line of direction and the principal visual direction coincide, but the former indicates the direction towards the eye, while the latter indicates the direction away from the eye. See law of identical visual directions.
Donders' line See demand line.
Egger's line See ligament of Wieger.
Ferry's line A line containing iron located in the corneal epithelium and adjacent to limbal filtering blebs. It may occur as a result of trabeculectomy.
line of fixation See fixation axis.
Fleischer's line See Fleischer's ring.
focal line Any astigmatic optical system produces two mutually, usually perpendicular, focal lines of a point object. The focal lines are situated at different image distances. Each focal line lies parallel to its associated cylinder axis. Syn. image line; line focus; Sturm's line. See circle of least confusion; conoid of Sturm; interval of Sturm.
line focus See focal line.
Fraunhofer's line's Fine dark lines distributed throughout the length of the solar spectrum due to the absorption of specific wavelengths by elements in the atmosphere of the sun and the earth. Fraunhofer observed about 600 of these lines and denoted the most prominent ones by letters from A in the extreme red to K in the violet. Examples: A corresponds to 759.4 nm, C to 656.3 nm, D to 589.3 nm, F to 486.1 nm, etc. See constringence; solar spectrum.
line of Gennari A distinctive white stripe in the middle of the fourth layer of the visual cortex containing the termination of the optic radiation fibres, as well as intracortical connections. The stripe appears above and below the calcarine fissure except in the most anterior part of the fissure where it only appears below. Syn. area striata; stria of Gennari. See visual area; calcarine fissure.
Hudson-Stähli line A yellowish-brown, more or less horizontal line containing iron which runs across the cornea below the centre. It occurs in normal corneas, more frequently in the elderly, or in association with corneal opacities.
iron line Deposits of iron within the corneal epithelium appearing as a brown rust line. They often subside with time leaving a nebulous scar. Several eponymous types have been described depending on the cause and location. See Hudson-Stähli line; Stocker's line; Coat's white ring; Fleischer's ring; siderosis bulbi.
median line Line formed by the intersection of the median plane and the plane of regard (Fig. L20). Syn. midline.
orthophoria line See demand line.
phoria line On Donders' diagram, it is the line joining all the points representing the passive position of the eyes corresponding to various levels of accommodation.
principal line of vision See line of sight.
pupillary line See pupillary axis.
retinal line Operationally, the collection of retinal elements that are activated in response to a line stimulus.
Sampaolesi's line A pigmented, wavy line anterior to Schwalbe's ring and found mainly in the periphery of the inferior cornea. It may be noted with gonioscopy in pigmentary dispersion syndrome and pseudoexfoliation syndrome.
line of Schwalbe See anterior limiting ring of Schwalbe.
line of sight Line joining the point of fixation to the centre of the entrance pupil. This line is more practical than the visual axis. Syn. principal line of vision.
line spectrum See line spectrum.
Stocker's line An abnormal line containing iron located in the corneal epithelium which may appear in front of the advancing edge of a pterygium.
Sturm's line See focal line.
visual line See visual axis.
|Table L3 Common spectral lines of the visible spectrum|
Synonym(s): linea [TA] .
Patient discussion about line
Q. My vision is blurry and I see zigzag lines, what is it from? Every now and again, usually after sitting a few hours in front of the computer or not sleeping enough at night, I start getting blurry vision. I see zigzag lines in front of my eyes and it can take sometimes an hour to go away. What is this from?
Q. what is the red line when your body temperature drops before you are getting hypothermia?
Q. can i get lung cancer from second hand smoking? what is the red line amount? how long do i need to expose to a smoking environment before i risk lung cancer ?