Year: 1886

page_text: Date of Application, 11th June, 1886
Complete Left, 11th Mar., 1887.
Complete Accepted, 26th Apr., 1887.
I, JOHN JAMES Woon, of 20 Lord Street Liverpool, in the County of Lancaster,
Optician do hereby declare the nature of my said invention to be as follows
My invention relates to the demonstration and detection of defective eyesight,
namely the detection of the greater, or lesser power of either eye, whether for
distance sight, or for reading sight and provides a means for the trial of correcting
lenses.
To the above end my invention consists in providing a means hereafter described,
whereby any person can themselves test the relative focal condition of each eye
alternately, whether for distance sight, or for reading sight, and can apply correcting
lenses showing the sight to be capable of improvement.
An apparatus according to my invention and whereby the same is carried into
practice consists, in the case of distance tests, of an upright standard provided with
sight apertures and eye pieces.-The said standard may have one or more sets of these
sight apertures to suit persons of different heights. These apertures are provided with
shutters which have a simultaneous alternate action, namely when the shutter for the
right eye is open, the shutter for the left eye is closed, and when the shutter for tho
left eye is open the shutter for the right eye is closed. This action may be obtained
in any convenient way for example by means of a spindle and milled button. In use
this apparatus is fixed at a distance of not less than fifteen feet from a sheet of test
types.
In operation the person looks through the eye pieces in the standard and by turning
the button alternately closes or shades each eye and thus tests their comparative power
for reading the test types.
For the purpose of correcting the defective vision and for equalising the sight, the
eye pieces are provided with grooves for the insertion of lenses by which the sight can
be improved or corrected.
In applying my invention for testing reading distance sight the standard provided
with the eye pieces is preferably diagonal and the test typo is placed at the usual
reading distance.

page_text: and Apparatus Employed therefor.
I, JOHN JAMES WOOD, of 20 Lord Street, Liverpool, in the County of Lancaster,
Optician, do hereby declare the nature of my said invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
My Invention relates to the demonstration and detection of defective eyesight,
namely the detection of the greater, or lesser power of either eye, whether for distance
sight, or for reading sight and provides a means for the trial of correcting lenses.
To the above end my Invention consists in providing a means hereafter described,
whereby any person can themselves test the relative focal condition of each eye
alternately whether for distance sight, or for reading sight and can apply correcting
lenses, showing the sight to be capable of improvement.
:
An apparatus according to my Invention and whereby the same is carried into
practice consists, in the case of distance tests, of an upright standard provided with
sight apertures and eye piece the said standard may have one, or more sets of these
sight apertures to suit persons of different heights. These apertures are provided
with shutters which have a simultaneous alternate action, namely when the shutter
for the right eye is open, the shutter for the left eye is closed and when the shutter
for the left eye is open the shutter for the right eye is closed. This action may be
obtained in any convenient way, for example by means of a spindle and milled button.
In use this apparatus is fixed at a distance of not less than fifteen feet from a sheet of
test types.
In operation the person looks through the eye pieces in the standard and by turning
the button alternately closes, or shades each eye and thus tests their comparative
power for reading the test types.
For the purpose of correcting the defective vision and for equalising the sight, the
eye pieces are provided with grooves for the insertion of lenses by which the sight can
be improved, or corrected.
In applying my Invention for testing reading distance sight, the standard provided
with eye pieces is preferably diagonal and the test type is placed at the usual reading
distance.
Examples of apparatus, or instruments illustrative of my Invention are given in
the accompanying two sheets of Drawings which form a part of this Specification
and are marked with figures and letters of reference corresponding with those used in
the following description of the same. Like figures and letters are used to denote like,
or corresponding parts throughout the various figures.
The instrument illustrated in sheet 1 of the Drawings in which Figure 1 is a side
elevation and Figure 2 a front view, represents the apparatus herein above set forth
for demonstrating and detecting defective eyesight for distance sight. It also
constitutes a means for trying corrective lenses. In the instrument A is the standard
having two sets of eye sights B, B', one for tall persons and the other for shorter
persons. The standard is secured to a stand C and can be adjusted up, or down upon

page_text: it by a thumb screw device b. a are the shutters one of each set being arranged to
be closed whilst the other is open. They are worked by suitable mechanism hereinafter
particularly described with reference to Figures 3, 4, and 5 of the Drawings, through
the button c. The mechanism is so arranged that when the shutter of one eye sight
aperture B is opened by turning the button c one way, or the other the other becomes
shut and vice versa. With reference to Figures 3, 4 and 5 (which represent an
apparatus for testing reading distance sight) the mechanism which I employ for this
simultaneously alternating shutter motion will be seen. It consists of toothed gearing
namely the shaft d on which the button c is mounted carries a barrel e to which one
of the shutters a is attached, whilst at the opposite end of the shaft d a tooth barrel f
is mounted which gears into a toothed segmental rack 9 and to which the other
shutter is attached. The shaft d and barrel fare mounted and work in bearings h.
It will be obvious that this gear gives a reverse motion to the shutters when the button
is moved either one way, or the other. The shutters a of each of the eye pieces B
and B in Figures 1 and 2 are provided with and operated by the above described
mechanism. The instrument is placed at a distance from the test type designated
by the letter. The distance is that usual for testing distance sight, namely it is
not less than fifteen feet. kare grooves, or slots in the eye pieces B and B' and are
provided for the purpose of correcting the defective vision and for equalizing
sight. This is done by inserting lenses into the slots by which the sight can be
improved, or corrected as will be understood.
The arrangement and construction of the instrument shown in Figures 3, 4, and 5
illustrates my Invention as applied for testing reading sight. Figure 3 is an elevation
in section through one of the eye pieces. Figure 4 is an outside view of the eye
piece and frame and Figure 5 is a cross section through the apparatus looking towards
the shutters of the eye piece. The instrument in this case has one set of eye pieces B
which are mounted on the machine frame A as shown. It is provided with and
supported by the stand C: indicates the position of the test type attached to the end
piece D, the distance between it and the eye pieces being the usual reading distance.
Having now particularly described and ascertained the nature of my said Invention
and in what manner the same is to be performed I declare that what I claim is
:-
First. In an eyesight testing apparatus, the herein described method of demon-
strating and detecting defective eyesight, which consists in simultaneously closing one
aperture and opening the other aperture substantially in the manner set forth.
Second. An Instrument, or apparatus for demonstrating and detecting defective
eyesight, consisting of eye picces, or apertures provided with shutters arranged to
simultaneously open one of such eye apertures and close the other, such eye pieces
being mounted on a standard as set forth.
Third. In an eye testing instrument, or apparatus the shutters a and operating
mechanism arranged and constructed substantially as set forth.
Fourth. An instrument, or apparatus for testing distance sight arranged and
constructed substantially as set forth with reference to Figures 1 and 2 of the
Drawings.
Fifth. An instrument, or apparatus for testing reading sight arranged and con-
structed substantially as set forth with reference to Figures 3, 4 and 5 of the
Drawings.