Note: Descriptions are shown in the official language in which they were submitted.
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BAC~CGROU~ID OF THE INVENTION
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Field of the Invention-
This invention relates to ophthalmic xerrac.ing
devices and has particular reference to a fixture for
~over refracting~ aphakics.
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Discussion of th'e Pri'or' ~rt
After rernoval of the crystalline lens and healing,
the eye has the potential for acu~e vision with correction '-
of the resultant refractive error. Success of the
procedure as ~udged by the patient, however, depends
primarily on the accuracy with which the refractive
error is corrected.
~est procedures for exploiting an aphakic eye's
potential are basically no different from those employed
in the working with of any refractive error. However,
management of the aphakic differs significantly in the
implementation of the refraction findings in a fitted
spectacles situation.
~hile unwanted optical errors may'go undetected in
low to moderate ophthalmic corrections, those of the
"cataract" range of approximately 10 times in amplitude
exact significant penalties in lens-eye performance.
Optimal dispensing requires precise knowledge of the
orientation of test lenses which during refraction,
yield comfort and ~aximum acuity. This may be accornplished
with a technique well ~nown and referred to as "over
refraction".
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Over refraction is practiced with a major spherical
component (e.g. a 12 diopter lens) glazed in t~e same or
similar frame to ~e dispensed and fitted carerully as if
for permanent wear~ By standard refraction ,est procedure,
; additional sphere and cylinder coxrections are determined
by placing sphere and cylinder test lens components
~efore the major component. The efficacy of this pro-
cedure is a consequence of duplicating in dispensing the
orientation which the ma~or spherical component occupied
in refraction.
In the practice of over refraction heretofor, a
spearate trial lens clip was clamped to each glazed
major componcnt fvr supporting the test lens components,
i.e. trial lenses. Each clip required separate vertical
and horizontal adjustment without means or benefit of
referencing with its counterpart. Accordingly, an assurance
of accurate similar alignment of trial lenses before the
two glazed major components and parallelism with the
spectacles frame is lac~ing, notwithstanding the drawbac~s
of general ungainliness in having to handle the clips
separately rather than as a unit and store the same in a
manr.er assuring against their separation and~or mis- -
placement of one from another.
In view of parallelism with the spectacles frame
and relative alignment of the trial lens holders being
critical to the results of over refraction, it is an
ohject of this invention to accomplish this in a uniquely
simple, inexpensive and cfficient manner.
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More particularly, it is another object of the
invention to provide an improved "over refraction" fixture
which overcomes the problems and drawbacks of prior art trial
lens clips.
Still another object is to provide an ophthalmic
fixture which has utility in the practice of refracting low to
moderate ophthalmic corrections as well as stronger refractive
errors of aphakics or other low-vision patients, the fixture
rurther having utility with unglazed, as well as glazed patient
fitted spectacles frames.
In accordance with the present invention, a pair of
trial lens holders are suspended right-angularly from a main
support bar. The holders are individually adjustable
along a portion of thé length of the bar and in directions
across the bar. Means are provided for maintaining the
right-angular disposi~ion of the holders at all positions of
adjustment along and across the bar. Means are provided for
manually detachably connecting the bar and trial lens holders
to a spectacles frame with the holders disposed forwardly of lens
supporting rims of the frame. The connecting means includes
locaters on the fixture for engaging uppermost brow portions of
the spectacles frame to establish parallelism of the fixture
and frame when the bar and trial lens holders are connected
thereto. Clamping arms terminated with V-grooved clampinq block
terminally engage portions of the frame below the brow portions
to retain the locaters in place against the brow portions when
the connection of the bar and trial lens holders is made. The
locaters comprise a pair of rollers earriecl by wires extendinq
from the main supporting bar and the clamping arms are proximally
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Lixed to the main support bar with respective extensions thereof
directed arcuately downwardly away from the bar to the clamping
blocks.
Other objects and advantages of the invention will
become apparent from the followlng description.
IN THE DRAWINGS
Fig. 1 is a front elevational view of a preferred
~mbodiment of the invention;
Fig. 2 is a side view-of the ophthalmic refracting
device of Fig. l;
Fig. 3 is a greatly enlarged fragmentary cross-
sectional illustration of a portion of a trial lens
holder of the refracting device, the cross-section being
taken approximately along lines 3-3 of Fi~
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Fig. 4 is a rear elevational view of the refracting
device illustrated in a position of use upon a spectacles
frame front;
Fig. 5 is a front elevational view of one trial
lens holder co~ponent of the re~racting device with a
cylindrical trial lens illustrated in a position of use
therein;
Fig. 6 is an elevational view of a spherical trial
lens exemplary of the type which may be positioned
immeaiately behind the trial lens of ~ig. 5.
Fig. 7 is a front elevational view of a modifica-
tion of the invention;
Fig. 8 is a rear elevational view of the refracting
2evice of Fig. 7 illustrated in a position of use upon
a spectacles frame front; and
Fig. 9 is a side view of the device of Figs. 8 and
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DE9CRIPTICN OF THE PREFERRED EMBODIMENTS
Referring more particularly to the drawings, t~i-
illustrated embodiment of the invention comprises trial
lens supporting fixture 10 adapted to be clamped to a
spectacles frame 12 (Fig. 4). While frame 12 need not
be glazed, it will be described hereinafter as having
the illustrated major spherical component lenses 14a
and 14b over which a final correction needed to co~pensate
for a patient's refracting error may be determined with
auxiliary trial (test) lenses used in fixture 10.
The structure of fixture 10 includes a normally
hori70ntally disposed main supporting bar 16 which, in
the form illu.strated, comprises a pair of tightly
juxtapositioned wires 18 having end caps 20.
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Extending from the central portion of bar 16 in
rearwardly spaced relationship therewith are wires 22.
These wires are terminated with grooved rollers 24
(Figs.2 and ~)which are adapted to fit against the
u?permost portions o. lens rims or brow portions of the
spectacles frame. This establishes parallelism of
fixture 10 with frame 120
Spring tensioned clamping arms 26 extend from
adjacent the central portion of bar 16 arcuately laterally
a~d downwardly to grooved blocks 28 which are pivotally
attached to the corresponding free ends of the arms.
As best shown in ~ig. 4, blocks 28 are each rocked into
engagement with a portion of the side and bottom of a
corresponding spectacles lens ri~m 30 and held thereinplace
under the spring tension cf arms 26 which, in turn,
locks frame 12 in place against locating rollers 24.
The illustrated section of sheathing 32 on bar lfi
merely aesthically conceals soldered or brazed connections
which may be used to unite wires 18, 22 and arms 26.
The sheating 32 may, however, comprise a metal ferrule
crimped or otherwise tightly fastened to bar 16 so as
to itself provide and/or reinforce the aforesàid connections.
Supported by bar 16 are right and left trial lens
holders 34a and 34b respectively. These holders, being
identical, will be described with reference to details
of holder 34a only.
~ iolder 34a comprises an upstanding necX 36 and
depending annular portion 38 having a trial lens receiving
and supporting pocket 40. Pocket 40 is provided with
two semi-circular trial lens comparhnents 42 and 44,
the latter disposed immediately forwardly of the former.
~7hile additional compartments may be provided if desired,
one compartment 42 suitable for supporting a spherical
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trial lens component is usually suf~icient as will
become more readily apparent hereinafter. The sphe~ical
and cylindrical trial lenses may be reversed in com?artrents
42 and 44, if desired. Opposite sides of each of
compartments 42 and 44 are provided with recesses 43
ana 45 respectively (Fig. 2) for permitting a full 180
rotation of a cylindrical trial lens placed in either.
Neck 26 of holder 34a is bifurcated as shown in
Figs. 2 and 3 with matching parallel serrations 46
internally of each extension of the ~ifurcation. These
serrations 46 extend horizontally across neck 36 and
fit snugly over wires 18 of bar 16 as illustrated in
Fig. 3. With holder 34a constructed of a rigid but
resilient plastic or other lightweight material including
lS metal, holder 34a may be adjusted upwardly and downwardly
on bar 16 by lifting or lowering the same with sufficient
force to cause serrations 46 to override wires-18.
With each increment of one wire 18 diameter, neck 36
will become fixealy snapped into an adjusted vertical
position on bar 16. Its vertical right-angular relation-
ship with bar 16 will, at the same time, be maintained
- by the parallelism of serrations 46. ~older 34a may be
readily horizontally slidably adjtlsted along bar 16
while at any vertically adjusted position. A ~rictional
2; force determined by the tightness of serrations 46
against wires 18 prevents accidental horizontal displace-
ment of the holder.
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A spacex 48 of a thickness selected in accordance
with the width of the bifurcation in neck 36 is provided
to establish the proper frictional fit of neck 36 over
wires 18.
~ndecia 50 (Fig. 1~ provide ~eans for indica~ir.
relative positions of vertical adjustment of holde-s
34a and 34b.
Refracting with fixture 12 may be accomplished 2S
follows:
A spectacles frame having a size, shape and style
appropriate for a particular low-vision patient, e.g.
zn aphakic, is selected.
For a patient needing a spherical correction other
than 12 diopters as is typical for the aphakic, the
frame is glazed with 12 diopter spherical lenses and
accurately fitted to the patient. It is so adjusted as
to locate optical axes of the 12 diopter spherical
components in such positions as to extend as accurately
as possible through the center of rotation of the eye
in each czse of each eye to be re,racted.
Fixture 1~ is applied to the spectacles rame as
illustrated in Fig. 4 and the frame is placed upon the
patient in a position corresponding to that intended
for permanent dispensing.
Annular portions of holders 34a and 34b are adjusted
horizontally and vertically into centered relationship
with respective optical axes of lenses 14a and 14b.
~7ith the frarne 12 and fixture 10 so positioned and
adjusted, refraction procedures are followed to determine
the sphere and cylinder ~with axis) which in combination
with the 12 diopter major component achieves maximum
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visual acuity. Being an over refraction technique,
this is accomplished by placing a spherical trial
~test) lens, e.g. lens 52 (Fig. 6), behin~ a cylindrical
trial lens 54 (Fig. 5~ in compartments 42 and 44 respectively
of poc`;et 40 in each of holders 34a and 34b. As mentioned
heretofore, lenses 52 and 54 may be revers~d in pocket
40, if desired.
The powers and cylinder axes of the trial lenses
are noied and used in co}nbination with the power of the
major spherical component to arrive at the patient's
prescription, e.g. for distance viewing correction.
Ne2r-viewing correction may be determined with a
plus sphere power trial lens of greater sphere power
than the distance trial lens introduced into one of
compart~ents 42 and 44. When a patient's working
distance is determined, that aspect of the final prescrip-
tion ~zy be conventionally computed.
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It s-nould be understood that the aforesaid procedure
is applicable to either monocular or binocular refraction
and that refraction procedures for certain low vision
patients may be practiced without the major spherical
components 14a and 14b, i.e. with an unglazed spectacles
.rz~e 12 and trial lenses only.
P~eferring more particularly to the modification of
the invention illustrated by Figs. 7, 8 and 9, fixture
lOa witQout the clamping arms 26 of fixture 10 is
provided with elastic strap 50 for attaching to a
spectacles frame i2a (Fig. 8). Strap S0 is fixed to
bar 16 over sheathing 32 with collar button-like fastener
52 held in place by spring clip 54. Fastener 52 protrudes
forwardly through clip 54 for receiving a selected one
of openings 56 in the free end of strap 50. Remaining-
parts of fixture lOa which correspond to similar parts
of fixture 10 are given like re~erence numerals and
need no further de.~3cription.
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In mounting fixture lOa upon frame 12a, grooved
xollers 24 are fitted against brow portion of frame 12a
to establish parallelism of frame lOa with frame 12a
(Fig. 8). Elastic strap 50 is extended beneath bridge
58 and upwardly over its connection to bar 16 whereupon,
with tension applied thereto, it is fixed in place ~y
slipping the nearest opening 56 over the forward
extension of fastener 52
~ith fixture lOa so fitted to frame 12a (as shown
in Fig. 8), its use for "over refractlon" may ~e practiced
as descri~ed hereinabove with reference to fixture 10.
In Fig. 9, there is illustrated a still further
modification of the invention which comprises the
placement of an annular cushion 60 around the division
62 between recesses 43 and 45 of pocket 40. This
cushion, which may be constructed of a flocked fabric,
~elt, velour, synthetic sponge rubber or other such
materials, is provided to prevent undue looseness of
trial lenses 52 and 54 in compartments 42 and 44 when
placed therein. While cushions 60 permit free rotation
of one or both of lenses 52 and 54, accidental displacement
from compartments 42 and 44 and/or rattling against the
compartment walls is avoided.
Those skilled in the art will readily appreciate
that there are various modifications and adaptations of
the precise form of the invention here shown and described
that rnay suit particular requirements. Accordingly,
the foregoing illustration is not to be interpreted as
restrlctive of the invention beyond that necessitated
by the following claims:
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