a. and sb. Also 6–7 visuall. [a. OF. visual (16th c., = Sp. and Pg. visual, It. visuale, OF. and F. visuel), or ad. late L. vīsuālis (rare) attained by or belonging to sight, f. L. vīsus sight, VISION sb.]
A. adj. 1. Of beams: Coming, proceeding or directed from the eye or sight. Obs. or arch.
1412–20. Lydg., Chron. Troy, I. 1697. Þat of oure siȝt þe stremys visual May nat be-holde, nor I-sen at al,… How Appollo is in his chare schynende.
1603. Holland, Plutarch’s Mor., 1362. It fareth with us in this case, as with those who would see a thing very farre distant; for of necessitie the visual beames of his sight doe faile before they can reach thereto.
1612. Drayton, Poly-olb., To Rdr. Trusting Authorities at second hand, and rash collecting … from visuall beam’s refracted through anothers eye.
1671. Milton, Samson, 163. For inward light alas Puts forth no visual beam.
b. Visual line, the direct line from the eye to the object or point of vision; the line of sight.
1571. Digges, Pantom., I. xx. F ij b. Agayne my line visuall proceeding from D to H the subtill notche in the subtendente side of the angle, extendeth to my fifte staffe G.
1602. Dolman, La Primaud. Fr. Acad. (1618), III. 696. By meanes of the shadowes, or visuall lines, representing the said shadowes.
1667. Sir R. Moray, in Phil. Trans., II. 474. The Visual line that passeth from the Eye to the upper-side of the Mark.
1755. Dict. Arts & Sci., s.v. Perspective, In drawing a perspective figure, where many lines come together, you may … draw the diagonals in red; the visual lines in black.
1850. Nichol, Archit. Heav., II. iv. 135. Merely to indicate that they lie in almost the same visual line, or that their proximity is optical only, and not real.
c. Visual ray, a ray proceeding from the eye to the object seen (cf. visual beam above), or in later use from the object to the eye.
1625. N. Carpenter, Geog. Del., I. vi. (1635), 154. The visuall Ray wherein the sight is carried is alwaies a right line.
1667. Milton, P. L., III. 620. The Aire, No where so cleer, sharp’nd his visual ray To objects distant farr.
1755. Dict. Arts & Sci., s.v. Perspective, The point of sight … is the point where all the other visual rays … unite.
1779. Phil. Trans., LXIX. 649. The great and varying refractions of the visual rays.
1815. J. Smith, Panorama Sci. & Art, II. 710. Visual rays, are those which, passing through the transparent plane, render original objects visible. Principal visual ray, is that which passes through the axis or centre of the eye.
1840. Lardner, Geom., 203. If the visual ray from the upper extremity A′ coincide with the visual ray from the upper extremity of the other.
1868. Lockyer, Guillemin’s Heavens (ed. 3), 475. The instrument will give us the angle formed by the visual ray with our base-line.
2. Of power or faculty: Pertaining or relating to, concerned or connected with, sight or vision.
1603. Holland, Plutarch’s Mor., 1345. As the one [sc. the sun] kindles, bringeth foorth and stirreth up the visuall power and vertue of the sense.
1798. Wordsw., Peter Bell, 918. The Spirits of the Mind Are busy … Upon the rights of visual sense Usurping.
1874. Carpenter, Ment. Phys., I. i. (1879), 13. That part of the Brain which is the instrument of our Visual Consciousness.
1889. Buck’s Handbk. Med. Sci., VII. 665/2. Comparative researches upon the visual acuity of different parts of the retina.
fig. 1828. Macaulay, Misc. Writ. (1860), I. 197. Language … when it becomes too copious,… altogether destroys the visual power [of the imagination].
1849. W. A. Butler, Serm., vii. 114. Faith is the realizing power. Its the visual sense of the Spirit.
3. Of organs: Endowed with the power of sight; having the function of producing vision. Cf. OPTIC a. 2.
1626. Bacon, Sylva, § 400. An Eye … hath beene thrust forth, so as it hanged a pretty distance by the Visuall Nerue.
1667. Milton, P. L., XI. 414. Michael … then purg’d with Euphrasie and Rue The visual Nerve [of Adam], for he had much to see.
1704. Swift, T. Tub, xi. The virtue of the Visual nerve, which every little accident shakes out of order.
1837. P. Keith, Bot. Lex., 228. An assemblage of several organs, all concurring to the production of a single result, constitutes an apparatus,—the visual apparatus, the digestive apparatus [etc.].
1874. trans. Lommel’s Light, 1. The visual organ, like every other special sense, possesses a peculiar form of sensibility.
1880. Huxley, Cray-Fish, iii. 121. Each of these visual pyramids consists of an axial structure—the visual rod invested by a sheath.
b. Of the eye, or in phrases denoting this, as visual orb. Chiefly poet.
1725. Pope, Odyss., I. 90. Neptune … Afflicts the chief, to avenge his giant son Whose visual orb Ulysses robbed of light. Ibid., IX. 454. Urged by some present god, they swift let fall The pointed torment on his visual ball.
1801. Lusignan, IV. 177. [She] complained that the light,… hurt the visual optic.
1877. L. Morris, Epic Hades, II. 221. By night when visual Eyes are blind.
4. a. Of knowledge: Attained or obtained by sight or vision.
In early use app. contrasted with book-knowledge.
1651. Biggs, New Disp., ¶ 74. Mathiolus, [etc.],… and other Herbalists, have hitherto been busied only about the features, and visuall knowledge of Plants, but all of them in like manner describe the vertues out of Dioscorides.
1903. J. Conrad & Hueffer, Romance, IV. v. 270. These … were the only two men of whom she could be said to have more than a visual knowledge.
b. Carried out or performed by means of vision.
1849. Robertson, Serm., Ser. I. x. (1866), 155. The visual perception of His Form would be a small blessing.
1882. Proctor, Fam. Sci. Stud., 8. The visual test however is independent.
c. Of impressions, etc.: Received through the sense of sight; based upon something seen.
1833. Sir C. Bell, Hand (1834), 327. Were the eye fixed in the head … we should still be capable of comparing the visual impression with the experience of the body.
1840. Mill, Diss. & Disc. (1859), II. 103. The visual ideas, which thus become our main symbols of tangible objects.
1877. M. Foster, Physiol., III. ii. (1878), 397. These two things we will briefly distinguish as visual sensations and visual judgments.
1879. Harlan, Eyesight, iii. 37. All parts of the retina are not equally sensitive to visual impressions.
5. Of or pertaining to vision in relation to the object of sight; = OPTIC a. 5, OPTICAL a. 2. Chiefly in special collocations as visual angle, axis, focus, point.
1710. J. Harris, Lex. Techn., II. *Visual angle, is the same with the Optick-Angle.
c. 1790. Imison, Sch. Arts, I. 205. The Visual or Optic Angle, is that which is contained under the two right lines drawn from the extreme points of an object to the eye.
1858. O. W. Holmes, Aut. Breakf.-t., xii. 110. To-day’s dinner subtends a larger visual angle than yesterday’s revolution.
1873. W. Lees, Acoustics, II. iv. 66. The size of an object depends upon the magnitude of the visual angle.
1874. Hartwig, Aerial World (1875), xiii. 198. If the sun rises, the visual axis sinks, and with it the rainbow.
1837. Goring & Pritchard, Microgr., 63. What may be called the *visual focus of a lens, or its distance from an object upon which we have adjusted its focus as a magnifier.
1867. J. Hogg, Microsc., I. ii. 156. The making of the actinic and visual foci coincident.
1679. Moxon, Math. Dict., s.v., The *Visual Point in Perspective,… is a point in the Horizontal Line, wherein all the Occular Rays unite. [Hence in Phillips, Harris, etc.].
1755. Dict. Arts & Sci., s.v. Perspective, Let the object you intend to delineate … be placed also on the right-hand of the visual point.
1842. Francis, Dict. Arts, Visual Point, the point of vision from which an object is viewed, synonymous with the point of sight.
b. In general use.
1812. Woodhouse, Astron., xi. 91. Certain smaller corrections belonging … to some change in the position of the poles of the earth: or to causes merely visual and optical.
1869. J. Martineau, Ess., II. 158. It is indeed quite conceivable that, in beings of another race, the visual scale may be much larger than ours.
6. That is an object of vision or sight; capable of being seen; perceptible, visible.
1756. Burke, Subl. & B., III. xxvi. A clear and settled idea of visual beauty. Ibid., IV. xv. Among many remarkable particulars that attended his first perceptions and judgments on visual objects.
c. 1810. Coleridge, in Lit. Rem. (1838), III. 295. The second commandment expressly makes the worshipping of God in or before a visual image of him … idolatry.
1853. Kane, Grinnell Exp., xxxv. (1856), 313. Refraction, with its preternatural augmentation of the visual hemisphere, revisited us.
1869. Tyndall, in Fortn. Rev., 1 Feb., 237. Of all the visual waves emitted by the sun, the shortest and smallest are those which correspond to the colour blue. Ibid. (1871), Fragm. Sci. (1879), I. vi. 223. The spectrum embraces three classes of rays—the thermal, the visual, and the chemical.
1892. Photogr. Ann., II. 240. Which from the visual aspect of colour should appear almost black.
b. Of actions, conditions, etc. Also, characterized by visibility.
1828. Carlyle, Misc. (1840), I. 307 (Goethe). Everything has form, everything has visual existence; the poet’s imagination bodies forth the forms of things unseen. Ibid. (1840), Heroes, ii. (1904), 69. That this so solid-looking material world … is a visual and tactual Manifestation of God’s power and presence.
1849. Ruskin, Sev. Lamps, v. § 10. 145. The inclination may be seen by the eye, by bringing it [the wall] into visual contact with the upright pilasters.
1867–77. G. F. Chambers, Astron., I. i. 11. The period required to make a whole visual rotation.
c. Of signalling or a signal.
1876. Voyle & Stevenson, Milit. Dict., 424/1. Visual signalling was formerly carried on by semaphores.
1895. Outing (U.S.), XXVI. 396/2. Visual signaling embraces flags, heliograph, torch, flash light, etc.
1906. T. B. S. Adair, in Times, 20 Aug., 5/1. I proceeded as far south of Lundy as ensured my being able to use visual signals to the signal station.
7. Of the nature of a mental vision; produced or occurring as a picture in the mind.
1845. Carlyle, Cromwell, I. 88. Let the reader try to make a visual scene of it as he can.
1851. Helps, Comp. Solit., x. 192. When we are thinking or talking of a person, we recall some visual image of that person.
1875. E. White, Life in Christ, I. v. (1876), 46. The deeper is the sense of incompetence even to imagine as a visual conception the mass of human beings who have tenanted it.
b. Carrying or conveying a mental vision or image.
1868. Gladstone, Juv. Mundi, xiii. (1870), 469. The Greek Catalogue is charged throughout with what I may call local colour and visual epithets; epithets which … raise up a prospect or scene before the mental eye of a reader or a hearer.
B. sb. 1. a. A visual ray: see VISUAL a. 1 c.
1726. Leoni, Alberti’s Archit., III. 2/2. Certain Rays which minister to the sight … are called Visuals.
1779. Phil. Trans., LXIX. 649. The quantity of effects and of errors in the visuals proceeding from this last cause must be very different at different times.
2. = VISUALIST 1.
1886. Mind, July, 415. This division of men into visuals, audiles, motiles and indifferents, as we may respectively call them, is of great interest and importance.
1899. Allbutt’s Syst. Med., VII. 440. These variations depend … upon the question whether the patients are ‘auditives’ or ‘visuals.’
