USRE19841E

USRE19841E - Clinical optical mensuration method

Info

Publication number: USRE19841E
Authority: US
Publication date: 1936-02-04

Description

Feb. 4, 1936. A. AMES. JR.. E' AL Re- 19,341

CLINICAL OPT-ICAI; HENSURATION METHOD AND INSTRUMENT Original Filed Aug. 13, 1929 5 Sheets-Sheet 1 delerw'* WIr/ fw Jr www? fyi- Feb.v 4; 1936. l f A. AMEs',^J,R E'rm.- R'e."l9,84l

CLINICAL OPTICAL MENSURTION METHOD AND INSTRUMENT original Filed Aug. 13. 1929', ssheets-sneef 2 fr@ www V Feb A. AMES,I JR.. ET Al. Re 19,341

CLINICAL OPTICAL MENS'URTION METHOD AND INSTRUMENT' "5 Sheets-Sheet 5 'original'Filed Aug. 1:5, 1929 7IIIII Feb. 4, 1936. A. AMES, JR.. Er AL Re- 19,841'

CLINICAL PTICAL MNSURATION' METHOD AND INSTRUIENI originali-md Aug. 13, 1929 -s sheets-sumarA 4 Feb 4 1936 A AMEs, JR., ETAL Re. 19,841

CLINICAL OPTICAL MENSURATION METHOD AND INSTRUMENT original Filed Aug. 13. 1929 s sheets-sheet 5 Ressued Feb. 4, 1936 CLINICAL OPTICAL vDIENSURA'ITION LIETHOD AdelbertAmes, Jr., and Gordon H. Gliddon, Hanover,'N. H., assignors to Trustees o! Dartmouth College, Hanover, N. H., a corporation of New Hampshire original'No. 1,944,811. dated January' 39.19.34. serial No. 385,611, August 13, 1929. Applica. tion for reissuev March 11,` 1935, Serial No.

Thisinvention relates to a methodand apparatus for the clinical determination of and men.

suration of the physiological optical condition oi the human eyes, for diagnosis and as an aid to the provision of corrective procedure or devices. l

. Objects of the invention are to provide a method oi and improved devices for the accurate clinical determination and mensuration of errors of joint perception oi visible objects by the eyes, or of each eye in respect to the other, or the normal expected perceptioni to provide a method and apparatus for the clinical determination and mensuration of horizontal vertical and cyclotorsional phorias and 4other conditions of stress '15 or imbalance; to provide means for the clinical .detection and measurement oi an associated phenomenon hereinafter referred to as retinal slip, and to provide means for the clinical investigation and measurement of certain asymmetries of perception ascribed to differing responses of the retinas to like objects'. These defects, which may also be described as retinal image asymmetry or ocular image asymmetry, and means for alleviating them are explained more in detail in the copending application of Adelbert Ames, Jr.

and Gordon H., Gliddon, Serial N0. 385,610, led

August 13,1929.

As herein used, the term retina comprises 'the brain elements corresponding to the retinal elements in the eyes proper an'd the nervous vtracts interconnecting these elements. The image asymmetry due to a dierence in the optical images formed by the dioptric apparatus of the eyes with vor without the aid of dioptric correction means, or to the anatomical or physiological diierences o! the retinal structure bringing` the dioptric images to consciousness, or to both,

may also be `referred to as differencevof ocular images, that is to say theactual total visual impression of an eye however obtained.

The apparatus of this invention improves vupon and supplements the` apparatus for clinical opti- Ycal mensuration described and claimed inthe application for patent oi Adelbert-Ames, Jr., Se-

rial No. 272,027,1iied April 23, 1928, and it is understood that in addition to the'new tests which can be made with the present device, all investigations i'or which the older instrument is suited can also be executed with the aid oi the apparatus to beA described herein. Investigation and determination oi perception phenomena. including the above-mentioned diilerent response of the retinas to comparable objects, that is the ocular image diilerence, involves the relation oi l ocultan` images in binocular vision, and their com- 39 claims. V(criss- 2m parison by relative adjustment thereof; is preferably carried out in connection with apparatus capable of fixing conditions for simultaneous binocular vision of the patients eyes, and may com-` prise comparison oi the perceptive reaction. to

images of like objects binocularly fused and uri--` like objects vnot iused, with provision for control and mensuration of vergence angles, retinal slip and ocular accommodation at diering distances of the respective objects.' In one aspectl the invention provides targets or objectholders having devices for' accurate measurement ci relative distance oi the objects in the field of view, of dimension in respect to each' other and of position or orientation in a plane at right angles to the axis oi vision.

The invention will now be described in connection with recommended specic forms only oi apparatus representative of` the genus of the invention and selected for illustration in the ac-` companying drawings, in' which Fig. 1 is a view in elevation of artarget; Fig. 2 `is a vertical longitudinal section oi.' the target shown in Fig.` l;

Fig. 3 isa diagram in plan oi onekindoi appurtenant apparatus with which the device or Figs. 1 and 2 may be used;

Fig. 4 is a rear elevation of a detail oi the target shown in Figs. land 2:

. Fig. 5 is a. iront elevation oran element of one oi the targets;

Fig. 6 is a iront elevation oi the head portion.

oi.' a modiedform o! target;

Fig. 6lv is a detail elevation of a complementary` part of another target made like Fig. 6;

7 is a detail section n line 1-1 of Fig. 6; Fig. 8 is'a detail right side elevation partly in vertical longitudinal section oi parts shown in F18. -6

target corresponding to Fig. 6;

Fig. 10 is a vertical section partly in elevation of parts shown in Fig. 9; and- Figs. l1, l2 and 13 are, respectively, elevations each showing a face view of a complementary pair o! replaceable or'variable objects adapted to be used one in eachof two of the targets. v

Referring now to Figs. l and 2, each member Fig.'9 is a iront elevation oi another form oi.'

oi a pair oi' targets may comprise a base I having a bottom grooved at 2 to fit over a straight slideway 3, 3* or' 3, Figs. 1 and 3, and a tubular column l bored to receive a screw l integralwith or attached to an enlarged split annular head 6 lhavl' ing lugs fora clamp screw l.

Column I is mii-led out to a parallel sided aperreilector.

` the heightof screw against a vertical scale I3 on column 4. Collar il may be fastened to screw 5 suitably, by a screw I4, for example. 'Ihe vertical position of screw 5 and its attachments is controlled by a knurled hand nut I5 taking against the machined upper face of column 4.

VAnnular head 6 may be clamped on the cylindrical hollow barrel I6 of a target head having a preferably integral annular flange 4I1 peripherally grooved at Il and concentrically recessed on one face at I9. Barrel I 6 may be closed at one end by an extension and head 2I having a concentric nipple 22 in which is mounted a socket 23 for a suitable incandescent lamp 24 lit by current leads 25; the interior oi' the lantern constituted by the barrel I6 and heads 24 and 2| may be enameled white or lined with a white substance or provided with any other suitable If it is desired to use a very bright and hot lamp at 24, not usually necessary, suitable holes may be provided at 26 for ventilation.

A dinusion screen of thin ground glass or other diffusion material, or a collar screen 28 may be mounted in the frontend of the bore of barrel I6,

against a slip ring 29, but this is not necessary' for the recommended types of light-emitting object discs 21, which maybe of any desired kind of translucent or opaque thin sheet body ca.-

pable of showing drawn, engraved, printed or vmail be discs madeof translucent or opaque stii Paper or white pigmented sheet material such as coated metal, celluloid or a phenolaldehyde condensation product, or any other suitable sheet substance, some having artificial star holes lil and the same or others having dark-line opaque visual objects II of any desired character, of which preferred forms will presently be explained. Any form 'of lantern capable of illuminating a bright point for an artiiicial'star may be substituted for the barrel II and lamp 24.

'I'he target discs 21 are preferably mounted by cementing or otherwise on a rotatably adjustable holder, as shown a fiat annulus 40 tting for rotation in the recess I9, and movable 'by either of two knurled-head shoulder screws 4I, -4I, in threaded holes in annulus'4 taking through

concentric sector slots

42, 42, Figs. 4 and 5, in flange I1, andbindingthebackface'of saidflange. Concentrlc with recess Il and annulus 4l the front surface of nange I1 is graduated in circular measure or asI shown, carries a scale 43, which as shown-'in Fig. 5 may-be graduated in each direction from at least one quadrant point through a 45 arc. An index mark I5 ,ona'nnulus 4lniayberealiasainst'scale4lV Y .l

The target headis preferably provided in addi;- tlmi to one of the ,21; .with a concentrically rotatable object adapted'to be mowed to vany anguiar position about the center `oi? a disc 215. As shown in Figs. 1 and 2 flange I1 may supportfor rotation an internally shouldered ring 44,havil18 an exterior' seat for a glass or other transparent disc 45, heldin place by annulus 41suitably fastened 44. Ring 44 may beturned. and

' groove I8. 'l

clamped by a binding 'screw 49 taking into 'Ihe interior face of' disc 45 is marked, preferably by pigment-filled engraving, to'constitute an object, typically the diametrical line 50, 'inline with a similarly constructed indexV mark 5I which may have an accompanying Vernier scale 52 reading against scale 43. These dispositions are such as to provide a target in which the mark or marks on the transparent rotatable element 46 may be inclined either to the target disc indications behind it or to a visually superposed image of an'- other target in projected concentric relation Ito it and its target disc, through a measured arc; andsuch as to provide, in the case of two similar targets, for accurate vertical and rotative adjustment for exact optical superposition of the central axis and rotation Aabout this axis of -two object targets; and affording provision for fused vision of two targets by both eyes, severally looking at each, when the targets are actually or virtually within the fusional amplitude of an observer whose. eyes are under examination. Additionally, each or either target has'at least two component elements adapted to be rotated on the same axis independently to an accurately measurable extent. It will be understood that displacement of the disc 21 in respect to the zero of` scale 43 may be measured accurately by alignment with the mark 50 -on disc 46,- displacements of which can be read by vernier 52; usually directreading of markv39 against scale 43 is sutilcient.

The races of the visual objects carried by the elements of the targets may be illuminated for vision by reflected light; for example,` each base I may carry for universal adjustment one or more illuminators, here shown as two small projectorsv 54, 55, each having an` incandescent lamp 58 and lens 51, mounted on lugs 58, 59, of base I, for

example by ball-and-pinch-socket linkages 60,'

5I as shown, and having suitable circuit connections 52, 63. In some cases itis desirable to light only Athe central areas within the border of discs 21, and the projectors 54, 55 may each be arranged to provide this. I f

For certain measurements of disagreement between the eyes of dimensional perception of objects severally perceived, it is desirable to provide arlV object quantitatively variable in dimension A of the glass'disc 46. with a metal bridge 65 having an edg'e 65 on a chord of the ring 44 and having a. hole for a shouldered screw 51 held by a flat nut 6l, Fig. 8 and having a-head bored and threaded transversely for a micrometer screw el, held against longitudinal movement by shoulders tak?v ing against faces of a slotted bearing 10 mounted on the face of a slide 1I slotted at 12 for 51, which holds it against bridge l5, slide 1I also having a longitudinal shoulder fitting against edge 65. On-one face of slide 1I', aiiependms rectangular glass plate 13 is cemented to more with slide 1| parallel with chord. ce in relation f -50 without'change of vergence, accommodationor distance. Usually, it is desirable to measure the trically to the axis by a distance measured by a scale 1I'L on slide 1I read against a vernier 1lb mounted on screw 61.

The corresponding object disc oi the complementary targets of this device may comprise an annulus 40 like the annulus 40 above explained, but it is preferred to have the actual objects movable a measurable distance toward and from the center. For this annulus 4l)n may be provided with `dovetail slots 40 for rack slides 15', 1'5 each having vernier scales 15*l to read against a scale 15b on the face of ring 401. Hand pinion shafts I 4|'L corresponding to the screws 4I and extending through the slots 42 have bearings in holes in the annulus 40e, and by these the slides 15 may be independently adjusted radially.

Ihe disc 21 may be slotted radially at 211, 21e over the slides 15, which may be of the same color and value as the disc 21. Each slide carries 0bject marks, sho'wn as articial star holes 30e. One of the complementary targets with the same slides 15 may, if desired, have on them at the same distances apart as the holes 3i)n broken lines 16, Fig. 6. nally lit.

In order to provide objects for fused vision of! the axis in respect to which there is no shift of position of the eye axes for determinations of discordant dimensional perception of one eye relative to the other, and referring now to Figs. 9, l0 and 13, one target may have a heterogeneous central object 'as 34, and the other a central star Vall, on the binocular combination of which objects, adjustments having been 4made for phorias as presentlyfexpl'ained, the patient's attention is fixed. Preferably dimensional `percep- In use lone target is not intertion is to be related to the fused-binocular perception of an object off the central axis, the inquiry by experiment being as to diil'erence in holes in a bearing lug 82 on frame 80 into which grooves studi-point screws 84 enter.

82, 82* respectively engage internally threaded Y nuts I5, 85| on projections erected from slides 8,1 having edges 88 bearing on an edge 80 of the frame 80 which defines a chord of the ring 44. The slides 81 have cemented thereto rectangular glass plates 90 teach of which is provided with an object, preferably the same kind of object, such as the lines 35 and '36. 'I'he lower ends of the glass plates 90, 91|n may be guided as shown be'-v hind one edge `of the frame 80. The slides B1 each may carry an index 88 reading against one of the scales 9i on frame 80 to measure displacement from center of the objects on yplates 90, 90e. 'Ihe devices of Fig. 6 and of Fig. 9 are rotatable with ring 44 about the center of the target as in thefcase of the device of Fig. 1,v y

Referring now to Fig. 3, and assuming vthe patient's eyes OS and OD to be placed so that Vtheir axes of rotation horizontally, vertically and by cyclotorsional motions are at o ando respectively, the apparatus, (which may be that described and claimed in the said application of 'The SCIEWS Adelbert Ames, Jr. Serial No. 272,027, led April 23, 1928 except as hereinspecifed) provides optically piane mirrors m, m', respectively perpen- `dicular to bisectors .of the angles o m T and o' m' Tl', T and VT being targets as hereinabove described. Slide tracks 3, 3a, a, and 3b, a' are respectively movable in a horizontal plane about centers in that plane as the ends of angular portions aand a coincident with the projection on that plane of the points o, o'; the mirrorsm and m are fixed to the tracks, and T and T ca n slide on the virtual optical axes by reflection in mirrors m, Jn. verged, parallelv or diverged, vision of a fused binocular composite o1' T and T is possible within the horizontal fusional amplitude of the patient, as if vthese targets occupied a position T", or to right or left` of that position and were directly viewed. In some cases the mirrors m, m' are half-silvered,` and a target at 'I2 maybe emportions of the targets. -Thes'e diaphragms may have differing polygonal openings and be used in out-of-focus position, and are useful to exclude Therefore, OD and OS being con-,

the outer portions of` the targets from fusedv binocular vision.

Referring to Figs. l1, 12 or 13, complementaryl L are placed at an angle (measurable in meter angles on scales :c and y, Fig. 3) to correspond to ocular convergence at distances '0, T, o. 'I'2 for normal binocular vision of an object at 'I'2 and the eyes are accommodated therefor, the central rings of Fig.. 11 will appear as one object. But if the target face having the stars 30* 30 only is dark, and the lamp 24 is lit, the eyes are disassociated, and the star images will not coincide with the dots 3|, 3|, unless the patient's eye viewing the artificial stars is free from muscular imbalance (horizontal or vertical phoria). 'A

central single star image will serve for this de- -f' termination, and the target for the other eye may be at T2. In either case the amount of angular adjustment of track 3b and of vertical adjustment by hand nut i5 of the internally lit target required to bring about coincidence measures and compensates for these phorias. s

Conditions may be reversed for the same determination for the other eye. Y

There are'many patients who are still unable.

when axial coincidence of star image and unlike corresponding mark is secured, to bring corresponding star and mark into coincidence because one system appears Vto be rotated about the other. This will occur whether or not there is actual fusion at the center, as Whenthe targets of Fig.

andior this purpose two targets having linear objects like 32h, 32 on the disc 46 aiord by readings of mutual or individual rotation of the discs M and report of limits of fusion or separation a valuable measurement. The apparatus described permits these and other measurements to be carried out at varying vergences and accommodations, which have significant relation to the comparative ocular function. f Also oi diagnostic signicance are phenomena which we have named retinal slip. In the case oi' fused vision on the like objects of'such targets as those of Fig. 11 or Fig. 12 (in which a diametrical line c-f star holes 30* corresponds to the gaps in similarly spaced vertical lines 3l) it has been observed that when the eyes are associated by convergence on and fused vision oi.'

'perceptive' error in this phenomenon, but the devices of Figs. 11 and 12 afford suilicient indica` tion of disappearance, direction and magnitude oi these phenomena by the report of the patient ci what he sees.

There are patientswho, when observingtargets of the kinds herein mentioned under conditions correcting phorias and the retinal slip phenomena, ii they should have such defects or, ii no such defects can be found, are nevertheless unable to secure perspective correlation of the unlike kinds vci' objects, and in whose eyes the identically spaced objects on the targets do not activate identically spaced retinal perceptions or identical ocuar images. Refractive ametropia being not present or eliminated, the phenomena demonstrate an asymmetry of retinal perceptionor ocular image diil'erence. In the case of the objects of Fig. 11, for example, these persons may note that the star images on one arm or another or throughout their distribution are spaced diilerently from the corresponding dots. Targets of the kind of Fig. 12 can be used in di'erent positions to investigate the quantity, sign and orientation of thesepeculiarities.` Local correction, on one side or the other, ior example, may be found bv changes of the relative positions oi' lines of vision from the eyes to corresponding objects or corrective lenses similar to lenses described in copending application 'Serial No. 385,610 for use in spectacles to be worn like the conventional eyeglasses. Such 'correction may involve overall size diil'erenceswhich are taken carexof by placing a size increasing lens before one eye or a size decreasing lens before the other eye. or, in extreme cases, by placing lenses having opposite effects in iront of eyes respectively. Meridional ocular image dir ferences or retinal asymmetry on a certain meridian are rectified with cylindrical size changing lenses, and defects which involve both over-all and meridional size defects can be corrected by an appropriate lens combination. VThese corrective lenses are placed between vthe eyes and the mirrors m, m (Fig. 3) as indicated at a, a', these lenses being supported in suitable holders which may be similar to those described in the above-mentioned copending application. Quantitative measurements of local displacement may be accurately made by use oi' the movable objects of the devices oi' Figs. 6 and 9. The procedure is to displace the slides of these devices to bring about local coincidence of the unlike ob- Y jects,` and measure the displacements scales of the apparatus.

In the kind oi target device shown in Fig. 13 for which see the devices of Figs. 9 and 10, ob jects capable of being fused are provided at 35, 35u on the movable slides for variation of their onthe distance severally from the axial star 30 and gap In the device of Fig. 6 motion of in line Il, the fused object could be utilized to determine asymmetry, but this involves a sluit oi the direction of attention. In case of the device oi' Fig. 9, attention remains ixed on the 'star and gapped line device, and the fused gure is displaced to bring about coincidence and investi-` functions structures and performances under variable conditions o! vergence and accommodation as will be apparent to those skilled in optical diagnosis.

We claim: i' 1. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination, apparatus permitting and inducing joint vision oi Atwo or more objects, one by each eye, and targets having thereonl like objects for visual fusion and unlike objects for appaient projection on each other specially arranged in reference to each other, whereby j udgment can be made of the relative displacement of the dissimilar objects. v

2. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination', apparatus permitting and inducing joint vision of, two or more objects, one by eachV eye, and targets having thereon like objects for visual fusion and unlike objects for apparent projection on each other, and means permitting one kind of object to be moved in relation to the other kind.

3. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination with apparatus inducing joint vision oi.' two or more objects. one by eachy eye, targets affording like objects for visual fusion and unlike objects for apparent projection on each other, means permitting one kind of object to be moved -in relation to the other kind, and means for measuring deviations ot the appearance of one kind of object from the other kind.

4. Apparatus for the clinical determination of errors oi joint ocular perception having therein in combination, apparatus permitting and inducing joint vision oi.' two or more objects, one by each eye, and targets having vthereon mutually related spaced series of like objects for visual fusion and similarly spaced unlike objects for apparent projection on each other, and means' permitting one kind of object vto be movedin relation to the other kind.

5. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination with apparatus inducing to vjoint. vision of two or morev objects, one by each eye.

targets aording like objects for visual fusion and unlike objects for apparent projection on each other and means permittinghorizontal, cycloangular, distance, and vertical adjustment of said targets severally.

6. Apparatus for the clinical determination of errors of joint ocular'perception-having therein in combination with apparatus for inducing joint vision of two or more objects, one by each eye, targets having thereon like objects for fusion and unlike objects respectively on each target in the same spacial relation, in combination with s means i'or moving the objects of one kind about an axis common to the binocular appearance of'y both kinds of objects. i

7. Apparatus for the clinical determination of errors 'oi joint ocular perception having therein in combination with apparatus for causing .joint vision oi two or more objects, one by each eye, targets characterized by objects respectively alike for binocular fusion and unlike but spacially similar, the respectiveobjects having elements severally rotatable about the virtual axes of the respective eyes in relation to each target. 8. Apparatus for the clinical 'determination of errors of joint ocular perception having therein in combination with apparatus for causing joint vision of two or more objects, one by each eye at variable vergences and variable virtual distances, targets characterized by objects respectively alike for binocular fusion and unlike but spacially simi-y lar, the respective objects being severally rotatable about the virtual axes of the respective eyes in relation to each target.

' 9. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination with apparatus for causing joint vision'of two or more objects, one by eacheye,

targets having provision forlvertical adjustment of an axis of rotation, and severally comprising a transparent member carrying an object for motion in respect to said axis, and a member having object markings adapted to be rotated about said 1 axis through substantial angles.

10. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination with apparatus for causing joint vision of two or more objects, `one `by each eye, targets having provision for vertical adjustment ot an axis of rotation, and severally comprising a transparent member carrying an object for motion in'respect to said axis and a member having object markings adapted to be rotated about said axis through substantial angles, and means permitting horizontal angular adjustment oi' the position oi' said targets in respect to the axis oi horizontal rotation oi' each eye.

1l. In a target device for optical mensuration `apparatus comprising' a plurality oi targets each comprising an object i-ield displaying visual objects, in combination, standards bearing complementar-y visual objects, at least one of said targets comprising a lantern for the illumination of an articial star hole in the object eld oi the target,vand at least one o t said targets comprising a sheet bearing a mark and means for turning said sheet through a measured angle about an axis perpendicular to said sheet and sai object eld.

12.4.In a target device for optical mensuration apparatus comprising a plurality oi targets each comprising an object ileld displaying visual ob-A jects, in combination, standards bearing complementary visual objects, at least one ot said tar-y -gets comprising a lantern for the illumination of an artificial star hole in the object ileld of the target, saidtargets each comprising a sheet bearing a mark and means for turning said sheet through a measured angle about an axis perpenf dicular tosaid sheet and object field, and at least one target comprising means for adjusting an object upon it toward and away from said axis.

i3. In a target device for optical mensuration apparatus comprising a plurality of targets, in combination, standards each bearing one of complementary visual objects, at least one of said targets comprising the object eld displaying visual objects, a lantern for the illumination of an articial star holeI vin the object ileld of the target, said targets each comprising asheet bearing a mark and means for turningsaid sheet through a measured angle about an axis perpendicular to said sheet and said object field, and at least one target comprising meansior adjusting, its objecteld device having an articial star hole in it toward and away from said axis.

14. In a target device for optical mensuration apparatus, the combination of a head having a ange and a recess, an annular holder i'or an object-sheet rotatable in said recess, a ring mounted for rotation on said flange, and a cooperating object mark carried by said ring for concentric rotation.

15. Target device for clinical optical mensuration apparatus having therein a scale for measuring rotation about a center, an annulus adapted to bear a disk object for rotation about said center, and a transparent sheet mounted for rotation about said center, said annulus' and sheet having indices related to said scale; and means for illuminating a hole in said disk object.

16. Clinical optical apparatus having therein a target having object markings including an arti-` iicial star hole in the target, means for illuminating the hole, and a complementary object mounted for lateral motion in respect to said 17. Clinical optical apparatus having thereina target having object markings including an articial star hole in the target, means for illuminating the hole, and two objects mounted for lateral motion in `respect to said hole and each other. r

18. `Apparatus vfor the clinical determination of errors oi' joint ocular perception having therein in combination with apparatus inducing joint vision of two or more objects, one by each eye, targets aording like objects for visual fusion and unlike objects for apparent projection on each other, means permitting horizontal, cycloangular, distance, and vertical adjustment oi said targets severally, means permitting one kind' ot object to be movedin relation to a target and the projected appearance oi objects of the other kind, and means for measuring deviations oi the appearance of one kind oir object from the other kind;

19. Apparatus for the' clinical determination of errors o1' joint ocular perception having therein in combination with apparatus inducing to joint visual perception oi' images severally formed in each eye of a patient of two or more objects, targets having parts constituting like objects for visual fusion by binocular vision andunlike objects for apparent projection on each other by binocular vision, and means for mounting said targets for horizontal angular adjustment in relation to each other.

20. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination with apparatus inducing to joint targets having parts constituting like objects for v visual fusion by binocular vision and unlike objects for apparent projection on each other by binocular vision, and means for mounting said* targets for several adjustment vertically through known distances in relation to the plane of the binocular axes. i

22. Apparatus for the clinical determination of errors of joint ocular perception having therein in combination with apparatus inducing to joint visual perception of images severally formed in each eye' of a patient of two or more objects, targets having .parts constituting like objects for visual fusion by binocular vision and unlike objects for apparent projection on' each other by binocular vision, and means for mounting said targets for several adjustment rotatively about an axis normal to their faces for cycloangular mensuration.

23. Apparatus for the clinical determination of errors of joint ocular perception having therein in'combination with apparatus inducing to joint visual perception of images severally formed in each eye of a patient of two or more objects,

V targets having parts constituting like objects for visual fusion lby binocular vision and unlike objects for apparent projection on each other by binocular vision, and means for mounting said.

' of one of the objects during simultaneous several vision of the respective eyes, and measuring the angular magnitude of the distortion of the' object for one eye in respect to the other eye required to obtain harmonious and symmetrical fused vision.

25. Apparatus for testing a pair of eyes com'- prising means for presenting to each eye the appearance of a fusion object, means for presenting to oneeye the appearance of a test object of one character placed on one side of said fusion object,y and means for presenting to the other eye the appearance of a test object of different character similarly placed in relation to said fusion object.l

,26. Apparatus according to claim 25, further characterized in that a plurality of test objects are placed symmetrically with respect to the fusion object.

27. Apparatus of the character referred to'comprising fusion means for causing a pair of eyes to converge at a predetermined distance, means for presenting to one of said eyes the appearance of test objects of one character denitely placed with respect to said fusion means, and means for concomitantly presenting to the other of said eyes 4the appearance of test objects of a diiferent characier similarly placed with respect to said fusion means.

28. Apparatus for the testing of a pair of eyes comprising means for forming on the retina of each eye like images adapted for binocular fusion, and mea-ns similarly disposed relative to said first means for forming on the several retinas unlike images.

29. Apparatus accordingto claim 28 further comprising means for changing the apparent separation in one eye relative to the.' other of the image formed by said second means.

30. 'I'he method of testing the human eye for variance in the size impressions of the ocular images of the two eyes comprising the formation of retinal images which are in part like and in part'unlike in the respective eyes, changing the relative positions of the like and unlike parts to cause the image in one eye to be similar in extent to that in the other eye, and measuring said change.

31. The methodaccording to claim 30 further characterized in that the eyes are, tested for meridional size variances by measuring the change necessary to make the radio ofdimensions on two different meridians of the image in one eye similar to the corresponding ratio of the image in the 32. The method of testing the human eyes for diiferences in size impressions thereof, comprising placing a chart in the line of vision of each eye, each chart having a. marking thereon fusible with the other and each chart having a marking thereon not fusible with the other, fusing the fusible markings with each other and measuring the apparent separation oi.' the non-fusible markings to determine the variance in size of images. 33. The method of testing a pair of eyes which comprises presenting to said eyes like semblances of an object and to each eye the form of a test object unlike the form presented to the other eye but similarly located with respect to each semblance, causing the eyes to fuse said semblances, and evaluating ocular defects by vobserving the apparent location of said unlike forms in blnocular vision determined by said fusion.

34. A device of the character described comprising visual objects having like objects thereon which may be fused and unlike objects thereon which cannot be fused, one visual object being positioned at a given distance from each eye, means for superposition of the ocular images o! said visual objects with each other, means for displacing the objects until the unlikeobjects assume a denite relation with each other, and means to measure said displacement to obtain the extent of phorias present.

35. A device of. the character described, comprising test means having fusible means thereon and non-fusible means given distance ir'om placing Ythe image of the non-fusible means of one eye relative to the corresponding image of the ,other eye, to place the non-fusible images in prefrom the eyes, to obtain Acating dimensional lrelative'size oi4 said images thereon positioned at a each eye, means forA disdetermined relation with each other, and means for measuring the extent of said displacement.

36. Apparatus for testing binocular vision for diiierence of the. ocularimages of. the two eyes, comprising test target means with elements indiproperties `thereof for forming in the respective eyes images whose dimensions may-be compared, means for relating the conscious appearances of the corresponding ocular images of said target means for comparison thereoi.' in vbinocular vision, means for lchanging the by adjusting the position of said elements until they assume a predetermined location in superposed appearance, and means for determiningthe amount of said adjustment'.

' 3'1.- Apparatus for testing binocular'vision for difference of the ocular images of the respective eyes, comprising a test object means before each eye inducing judgment of at least one dimension, means for relating conscious appearances oi the ocular images oi said test object means yfor comparison thereof., means for .adjusting the relative dimensions of said test object means as perceived through the respective eyes, while substantially maintaining the distance oi the respective images a dimensional relation stantially of said ocular images, and means for measuringy the amount oi said adjustment.

38. The method of testing binocular vision i'or difference o! the ocular images oi the two eyes, comprising the formation in the respective eyes of images of test target means which have elements indicating dimensional properties of said target means, and whose relative positions may be compared, superposing the conscious appearances of the corresponding ocular images ci said target means for comparison thereof in binocular vision, changing the relative size of said images by adjusting the position of said, elements until they assume a predetermined location in superi posed appearance, and oi' said adjustment. 39. In the art of determining the amount son which comprises presenting to each eye of the person a test object means with elements for dimensional comparison relating the conscious apmeans for comparison thereof, adjusting the relative dimensions of. said test object means as appearing through the respective eyes while submaintaining the distance of the re` spective images from the eyes, to obtain a dimensional relation of said ocular images, and measuring said adjustment.v 4

ADELSERT AMES, Jn. GoaDoN H. GLmDoN.

testing binocular vision the n method of correlating the ocular images of a per-