acuity of vision
Fr.: acuité visuelle
The ability of the → eye to see separately two points close to each other. It is a measure of the → resolving power of the eye's → optical system and depends on the density of cells in the → retina. The maximum acuity of the normal human eye is around 0.5 minutes of arc.
arc of vision
Fr.: arc de vision
negâh-e kaž (#)
Fr.: regard oblique
The technique of looking slightly to the side of a faint object being studied while continuing to concentrate on the object. The technique helps bring out details which otherwise would be missed by looking directly at an object. The reason is that the portion of the eye's retina that best detects dim light (fovea) is located all around the edges rather than the center.
Negâh, → vision; kaž "averted."
šekâf-e Cassini (#)
Fr.: division de Cassini
The main dark gap, 4,700 km wide, which divides Saturn's outermost A and B rings.
Named after Jean-Dominique Cassini (1625-1712), French astronomer of Italian origin, who discovered the division in 1675; → division.
1) baxš; 2) šekâf
1) The act or process of dividing; state of being divided.
From O.Fr. division, from L. divisionem (nom. divisio), from divid-, stem of dividere "to cleave, distribute," from → dis- "apart" + -videre "to separate," from PIE base *widh- "to separate."
1) Baxš "portion, part, division," baxšidan "to divide,
distribute, grant;" Mod./Mid.Pers. baxt "fortune, fate," baxtan, baxšidan
"to distribute, divide," bâq "garden," initially "piece or patch of land,"
baq "god, lord;" Av. bag- "to attribute, allot, distribute,"
baxš- "to apportion, divide, give to,"
baxta- "what is allotted (luck, fortune),"
baxədra- "part, portion," baγa- "master, god;"
O.Pers. bāji- "tribute, tax;" cf. Skt. bhaj- "to share, divide,
distribute, apportion," bhájati "divides," bhakta- "allotted; occupied
with; a share; food or a meal, time of eating?" pitu-bháj-
"enjoying food;" Gk. phagein"to eat (to have a share of food)";
PIE base *bhag- "to share out, apportion."
Fr.: signe de division
A symbol placed between two quantities (dividend and the divisor) to indicate the division of the first by the second. The division sign is written as a horizontal line with dot above and dot below, ÷ (→ obelus), or a slash or horizontal line.
Fr.: vision double
Same as → diplopia.
Fr.: division euclidienne
Fr.: division de Huygens
šekâf-e Liyot (#)
Fr.: division de Lyot
In Saturn's rings, the gap between rings B and C.
Fr.: vision périphérique
In optics, the ability to see over large angles of view.
the act or work of revising. a process of revising. a revised form or version, as of a book.
Verbal noun of → revise.
Fr.: vision scotopique
Vision that occurs when the eye is dark-adapted. In scotopic vision, the level of luminance is so low that the retinal cones are not stimulated, and there is no color vision. Same as scotopia; → dark adaptation.
Scotopic, from L. Gk. skoto- combining form of skotos "darkness" + -opia akin to ope "view, look," ops "eye, face;" → vision.
Did, → vision; târiki noun from târik "dark," Mid.Pers. târig "dark," târ "darkness," Av. taθra- "darkness," taθrya- "dark," cf. Skt. támisrâ- "darkness, dark night," L. tenebrae "darkness," Hittite taš(u)uant- "blind," O.H.G. demar "twilight."
Fr.: division synthétique
A method of dividing a polynomial in the special case of dividing by a linear factor. Synthetic division allows one to do long division problems much quicker. It is related to the → Ruffini-Horner method.
M.E., from O.Fr. vision, from L. visionem (nominative visio) "act of seeing, sight, thing seen," from p.p. stem of videre "to see," cognate with Pers. bin, present stem of didan "to see" (Mid.Pers. wyn-; O.Pers. vain- "to see;" Av. vaēn- "to see;" cf. Skt. veda "I know;" Gk. oida "I know," idein "to see;" PIE base *weid- "to know, to see").
Negâh, "look," from Mid.Pers. nikâh "look, glance, observation;" Proto-Iranian *ni-kas- "to look down," from ni- "down, below," → ni- (PIE), + *kas- "to look, appear;" cf. Av. nikā-, nikāta- (in the name of the 15-th nask) "that which is observed," ākas- "to look;" Mid.Pers. âkâh, Mod.Pers. âgâh "aware, knowing;" Skt. kāś- "to become visible, appear;" Ossetic kast/kaesyn "to look;" did, from didan "to see" (Mid.Pers. ditan "to see, regard, catch sight of, contemplate, experience;" O.Pers. dī- "to see;" Av. dā(y)- "to see," didāti "sees;" cf. Skt. dhī- "to perceive, think, ponder; thought, reflection, meditation," dādhye; Gk. dedorka "have seen").