DE416968C - Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye in order to image the far point of the eye at infinity - Google Patents
Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye in order to image the far point of the eye at infinityInfo
- Publication number
- DE416968C DE416968C DEZ14229D DEZ0014229D DE416968C DE 416968 C DE416968 C DE 416968C DE Z14229 D DEZ14229 D DE Z14229D DE Z0014229 D DEZ0014229 D DE Z0014229D DE 416968 C DE416968 C DE 416968C
- Authority
- DE
- Germany
- Prior art keywords
- eye
- infinity
- refractive index
- image
- far point
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
- A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
- A61B3/103—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for determining refraction, e.g. refractometers, skiascopes
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Medical Informatics (AREA)
- Biophysics (AREA)
- Ophthalmology & Optometry (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Physics & Mathematics (AREA)
- Molecular Biology (AREA)
- Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Eye Examination Apparatus (AREA)
Description
Apparat zur objektiven Messung des Brechwertes des Brillenglases, das einem fehlsichtigen Auge vorzuschalten ist, um den Fernpunkt des Auges im Unendlichen abzubilden. Bei der Benutzung eines Apparates nach dem Hauptpatent hat sich der Mißstand ergeben, daß die angewandte Beleuchtung, um das auf der Netzhaut des zu untersuchenden Auges entstehende Schattenbild des Strichkreuzes für den Beobachter noch deutlich erkennbar zu machen, auf der Netzhaut eine so starke Flächenhelligkeit erzeugt, daß Blendungserscheinungen des zu untersuchenden Auges eintreten. Diese führen zu Störungen der Untersuchung, wie z. B. starker Zusammenziehung der Pupille oder' Tränenfluß. Wie sich gezeigt hat, läßt sich ein Ausweg finden, da die Reizung des zu untersuchenden Auges nicht allein von der Flächenhelligkeit der Beleuchtung auf der Netzhaut, sondern auch von der. Gesamtmenge des dem Auge zugeführten Lichtes abhängt. Nach der- Erfindung ist darauf verzichtet, die Netzhaut für den Beobachter in einem weiteren Umfange sichtbar zu machen, als für die Messung unbedingt erforderlich ist. Zu diesem Zweck ist das Strichkreuz mit einer undurchsichtigen Scheibe verbunden, die nur.in der unmittelbaren Nachbarschaft des Strichkreuzes Licht hindurchtreten läßt. Es hat sich gezeigt, daB man auf diese Weise die Netzhaut in den in Frage kommenden kleinen Bereichen stark genug beleuchten darf, um sich das Schattenbild des Strichkreuzes deutlich abheben zu lassen, ohne daß störende Reizungen. auftreten.Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye, around the far point of the eye at infinity map. When using an apparatus according to the main patent, the Illness revealed that the lighting applied to that on the retina of the too The shadow of the cross of the line created by the examining eye for the observer still clearly recognizable, such a strong surface brightness on the retina generated that glare of the eye to be examined occur. These lead to disruptions in the investigation, such as B. severe contraction of the pupil or 'lacrimation. As has been shown, a way out can be found because of the irritation of the eye to be examined not only from the surface brightness of the lighting on the retina but also from the. Total amount of light supplied to the eye depends. According to the invention, the retina for the observer is dispensed with to make it visible to a wider extent than is absolutely necessary for the measurement is. To that end is the cross with an opaque one Disc connected only. In the immediate vicinity of the line cross Lets light pass through. It has been shown that in this way the retina can be seen in the small areas in question may illuminate strongly enough to keep yourself to let the silhouette of the line cross stand out clearly without disturbing Irritation. appear.
Die Anwendung einer kreuzförmigen Blende bei einem Apparat zur Augenuntersuchung ist schon in der Patentschrift 205177 vorgeschlagen, worden. Dort handelt es sich jedoch darum, das Spiegelbild zu beobachten, das die Hornhaut des zu untersuchenden Auges von einer Lichtquelle entwirft, und die Blende soll das Entstehen von Nebenbildern verhindern.The use of a cross-shaped diaphragm in an apparatus for eye examination has already been proposed in patent specification 205177. There, however, it is a matter of observing the mirror image that the cornea of the eye to be examined creates from a light source, and the diaphragm is intended to prevent secondary images from occurring.
Die dargelegte Lichtverteilung hat natürlich auch dann ihre Bedeutung, wenn das 'Strichkreuz nicht drehbar ist.The light distribution presented is of course also important if the crosshair cannot be rotated.
In der Zeichnung ist die Erfindung durch ein Beispiel erläutert.The invention is illustrated by an example in the drawing.
Abb. r zeigt eine Glasscheibe a, die, wie die Scheibe e des Ausführungsbeispiels des Hauptpatentes, mit einem Strichkreuz und einer Kreismarke ausgestattet ist. Abb.2 zeigt eine Blechscheibe b mit einem kreuzförmigen Ausschnitt in der Mitte. Abb. 3 zeigt die beiden Scheiben so aufeinandergelegt, daß nur in der unmittelbaren Umgebung der Kreuzarme Licht hindurchtreten kann. Abb. q. zeigt die aufeinanderliegenden Scheiben im Querschnitt.Fig. R shows a glass pane a, which, like the pane e of the exemplary embodiment of the main patent, is equipped with a cross and a circle mark. Fig.2 shows a sheet metal disk b with a cross-shaped cutout in the middle. Fig. 3 shows the two discs placed on top of each other so that only in the immediate Light can pass through the area around the arms of the cross. Fig.q. shows the superimposed Slices in cross section.
Statt einer besonderen undurchsichtigen Scheibe könnte man die Wirkung einer solchen auch dadurch erzielen, daB man die Glasscheibe mit einem entsprechenden undurchsichtigen Überzug versähe. Abb. 5 zeigt eine solche Scheibe a im Querschnitt.Instead of a special opaque pane, you could have the effect This can also be achieved by fitting the glass pane with a corresponding provide an opaque coating. Fig. 5 shows such a disk a in cross section.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEZ14229D DE416968C (en) | 1924-02-09 | 1924-02-09 | Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye in order to image the far point of the eye at infinity |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DEZ14229D DE416968C (en) | 1924-02-09 | 1924-02-09 | Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye in order to image the far point of the eye at infinity |
Publications (1)
Publication Number | Publication Date |
---|---|
DE416968C true DE416968C (en) | 1925-07-31 |
Family
ID=7623505
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DEZ14229D Expired DE416968C (en) | 1924-02-09 | 1924-02-09 | Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye in order to image the far point of the eye at infinity |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE416968C (en) |
-
1924
- 1924-02-09 DE DEZ14229D patent/DE416968C/en not_active Expired
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0327693B1 (en) | Ophthalmic device | |
DE2614273A1 (en) | COMBINATION DEVICE FOR EYE EXAMINATION | |
EP0924494A2 (en) | Topometer for shining surfaces | |
DE416968C (en) | Apparatus for the objective measurement of the refractive index of the spectacle lens, which is to be connected in front of a defective eye in order to image the far point of the eye at infinity | |
DE2716614A1 (en) | OPTICAL SYSTEM FOR EXAMINATION OF THE RETINA | |
DE539515C (en) | Method and device for determining the curvature of the cornea | |
DE3437234C2 (en) | Device for determining the potential visual acuity using a slit lamp microscope | |
DE10009532A1 (en) | Quality assurance method for eye operations involves using binocular observation instrument to observe surface of eye and test card projected onto retina through eye lens | |
DE697040C (en) | Optical component | |
DE387251C (en) | Viewfinder for photographic chambers | |
DE1572670B2 (en) | OPTICAL SIGHTING DEVICE | |
DE650073C (en) | Device for checking the surface quality of curved, reflective bodies in reflected light | |
DE847215C (en) | Wide angle eyepiece | |
DE4107070A1 (en) | Two-part flame chromate lens unit - has thick fluorspar-glass collector lens between twin-lens sets | |
DE456169C (en) | Eye refractometer | |
DE720272C (en) | Method and device for checking the position of the glasses relative to the eyes of the wearer | |
DE632768C (en) | Photographic light meter | |
DE861975C (en) | Reflex sight | |
DE379910C (en) | microscope | |
DE613786C (en) | Hand-held eye mirror | |
CH206746A (en) | Photographic apparatus with light meter attached. | |
DE610076C (en) | Ophthalmoscope | |
DE758685C (en) | Eye examination device | |
DE356009C (en) | Ophthalmoscope with a simultaneous lighting and observation system consisting of reflectors | |
DE528478C (en) | Reflexless eye refractometer |