CN115112354A - Device and method for testing field angle of fundus camera - Google Patents

Device and method for testing field angle of fundus camera Download PDF

Info

Publication number
CN115112354A
CN115112354A CN202210748820.3A CN202210748820A CN115112354A CN 115112354 A CN115112354 A CN 115112354A CN 202210748820 A CN202210748820 A CN 202210748820A CN 115112354 A CN115112354 A CN 115112354A
Authority
CN
China
Prior art keywords
fundus camera
field angle
scale
base
glass cover
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.)
Pending
Application number
CN202210748820.3A
Other languages
Chinese (zh)
Inventor
王建中
周旭晨
任志祥
林俊
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiangsu Fuhan Medical Industry Development Co ltd
Original Assignee
Jiangsu Fuhan Medical Industry Development Co ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Jiangsu Fuhan Medical Industry Development Co ltd filed Critical Jiangsu Fuhan Medical Industry Development Co ltd
Priority to CN202210748820.3A priority Critical patent/CN115112354A/en
Publication of CN115112354A publication Critical patent/CN115112354A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties
    • 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
    • A61B3/12—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for looking at the eye fundus, e.g. ophthalmoscopes
    • 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
    • A61B3/14—Arrangements specially adapted for eye photography
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties
    • G01M11/0207—Details of measuring devices
    • G01M11/0214—Details of devices holding the object to be tested
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N17/00—Diagnosis, testing or measuring for television systems or their details
    • H04N17/002—Diagnosis, testing or measuring for television systems or their details for television cameras

Abstract

The invention provides a device and a method for testing the field angle of an eye fundus camera, the device comprises a base and a glass cover which is hermetically arranged on the base, the bottom of the base is provided with an air suction hole for connecting an air suction pump, the base is provided with a support which is arranged inside the glass cover, the base is provided with a display screen for displaying a standard part ruler, the support is connected with a cross rod through a fixing clamp, the cross rod is provided with a storage rack, the bottom of the storage rack is provided with a pulley which can move on the cross rod, the pulley is connected with a stepping motor, and the bottom of the storage rack is provided with the eye fundus camera. The invention does not use an eyeball model, thereby avoiding the influence of the medium on the observation light path in the prior art and ensuring more accurate test results.

Description

Device and method for testing field angle of fundus camera
Technical Field
The invention belongs to the technical field of medical instrument inspection and detection, and particularly relates to a device and a method for testing the field angle of a fundus camera.
Background
In the design process of a child fundus camera, the field angle of an optical lens needs to be tested, the current method for testing the field angle is to directly measure by using a simulated eyeball, the simulated eyeball is a model with optical characteristics similar to eyes, the corneal curvature, refractive index of a refraction medium and the like of the simulated eyeball are very close to the parameters of a real eyeball, and the simulated eyeball is usually used for simulated shooting in medical teaching activities and fundus camera research and development testing stages. One commonly used eyeball model is a liquid injection eyeball model, which has optical characteristics closer to real eyeballs than a non-liquid injection eyeball model, and is widely applied to fundus camera testing and medical personnel practicing operations. However, after the liquid injection eyeball model is used for a period of time, due to the fact that temperature changes cause expansion and contraction of oil, bubbles are prone to floating in the oil, and particularly after air transportation and carrying, the bubbles can be generated at a high probability due to air pressure changes and need to be repaired by professionals. In medical teaching activities or fundus camera research and development tests, when the inside of an eyeball model is observed through a cornea, air bubbles appear in an observation optical path to influence normal observation, so a new method for testing the field angle of a fundus camera needs to be tried.
Disclosure of Invention
In order to solve the problems, the invention discloses a device and a method for testing the field angle of a fundus camera, which do not use an eyeball model, avoid the influence of a simulated eye medium on an observation light path in the prior art and ensure more accurate test results.
In order to achieve the purpose, the technical scheme of the invention is as follows:
the utility model provides a testing arrangement of fundus camera angle of vision, is in including base and sealed setting glass cover on the base, the base bottom is provided with an aspirating hole that is used for connecting the aspiration pump, be provided with one on the base and arrange in the inside support of glass cover, be provided with a display screen that is used for showing standard component scale on the base, connect the horizontal pole through mounting fixture on the support, install supporter on the horizontal pole, supporter bottom is provided with can the pulley of removal on the horizontal pole, the pulley connect step motor, supporter bottom installation fundus camera.
Further, a bar-shaped LED light source is arranged at the bottom of the cross rod, and the horizontal position of the bar-shaped LED light source is higher than the lens of the fundus camera.
Furthermore, a laser range finder for measuring the distance from the bottom of the fundus camera to the display screen is arranged on the fixing clamp, and the laser range finder is installed on the fixing clamp through a sliding rail.
Further, set up the recess that is used for placing the glass cover on the base, set up the silica gel pad in the recess, the glass cover is closely installed on the silica gel pad, the base still sets up the bayonet socket that is used for the support block.
Furthermore, the glass cover is of a double-layer structure and sequentially comprises a diffuse reflection layer and a light absorption layer from inside to outside, the light absorption layer is formed by coating light absorption paint with the thickness of 5mm on the outer surface of the glass cover, and the internal diffuse reflection layer is a diffuse reflection light reflection film arranged inside the glass cover and used for simulating the light state inside eyeballs.
The method for testing the visual angle of the fundus camera by using the testing device for the visual angle of the fundus camera comprises the following steps:
s1, determining the scale of a standard part scale through calculation, and displaying the standard part scale obtained through calculation on a display screen;
the specific method for determining the scale of the standard part scale through calculation comprises the following steps: because the average refractive index of the human eye 1.333 is different from the refractive index of air 1, the field angle β of the fundus camera in the human eye and the field angle α of the fundus camera in the air can be converted according to the following formula: α = (1.333/1) × β, that is, α =1.333 × β, and by projection, a circle corresponding to the corresponding visible angle is made on the plane, that is, the circle of the standard scale, and the circle radius r of the standard scale 2 = arctan(α/4)*2r 1 ，r 1 The radius of the human eye; human eye radius r for different people 1 Converting the radius r of the ring of the different standard scales 2 Shown as a set of concentric circles;
s2, fixing the fundus camera on a storage rack, enabling the center of a lens of the fundus camera and the circle center of a concentric circle on a standard component ruler to be on the same straight line, and turning on a strip-shaped LED light source;
s3, buckling the glass cover on a silica gel pad of the base, connecting an air pump with an air exhaust hole, opening the air pump, and exhausting air in the glass cover to form a vacuum environment;
s4, opening a scale of the standard component displayed by the fundus camera observation display screen, placing the fundus camera on a storage rack, aligning the lens center of the fundus camera to the circle center of the scale of the standard component, observing the visual range of imaging at a position 20mm away from the display screen, and directly reading the field angle beta of the fundus camera on human eyes on the scale of the standard component.
The invention has the beneficial effects that:
because the simulated eye is used for testing the field angle, the simulated eye needs to be manufactured according to the radius of the human eye, and the fundus camera with an unknown field angle is used for measurement after the simulated eye is manufactured, so that time and labor are wasted, materials are wasted, and the operation is troublesome; the device and the method can directly display the required standard piece according to the diameter of human eyes, and the handle is placed on the storage rack, so that the field angle can be directly measured, the operation is simple, the error of manually shooting simulated eyes is reduced, and the measurement result is more accurate.
Drawings
FIG. 1 is a schematic structural view of the present invention;
FIG. 2 is a schematic structural view of a stent section of the present invention;
FIG. 3 is a schematic view of the construction of the horizontal rail portion of the present invention;
FIG. 4 is a schematic illustration of the present invention determining the scale of a master scale;
fig. 5 is a view of the field angle of the fundus camera at the simulated eye.
Detailed Description
The present invention will be further illustrated with reference to the accompanying drawings and detailed description, which will be understood as being illustrative only and not limiting in scope.
Example 1:
as shown in fig. 1-3, the fundus camera angle of view testing device of this embodiment includes a base 8 and a glass cover 2 hermetically disposed on the base, the bottom of the base is provided with an air suction hole 3 for connecting an air suction pump, the base is provided with a support 6 disposed inside the glass cover, the base is provided with a display screen 7 for displaying a standard component ruler, the support is connected with a cross rod 61 through a fixing clamp 62, the cross rod is provided with a shelf 1, the bottom of the shelf is provided with a pulley 11 capable of moving on the cross rod, the pulley is connected with a stepping motor 12 for aligning a fundus camera with the center of the standard component, and the bottom of the shelf is provided with the fundus camera.
Display screen 7 is connected with the singlechip, and the singlechip is used for calculating the standard component scale that each angle corresponds, the scale is the ring that shows on display screen 7 promptly, except showing each ring, display screen 7 can also show the error range that each ring represents, if: the corresponding ring of 130 degrees is displayed, and the rings with errors of +/-5 percent (namely error rings of 123.5-136.5 degrees) are displayed on two sides of the 130-degree ring, and the error rings are displayed by dotted lines, which is a technical effect which cannot be achieved by the traditional simulation eye.
In this embodiment, a bar-shaped LED light source 5 is disposed at the bottom of the cross bar, and the horizontal position of the bar-shaped LED light source is higher than the lens of the fundus camera, so as to simulate the process of the light source entering the eyeball from the pupil to the retina.
In this embodiment, the fixing fixture is provided with a laser range finder 4 for measuring the distance from the bottom of the fundus camera to the display screen, and the laser range finder is mounted on the fixing fixture 62 through a slide rail 63.
In this embodiment set up the recess that is used for placing the glass cover on the base, set up silica gel pad 81 in the recess, the glass cover is closely installed on the silica gel pad, the base still sets up the bayonet socket that is used for the support block.
In this embodiment, the glass cover is of a double-layer structure, and the light absorption layer and the diffuse reflection layer are sequentially arranged from inside to outside, the light absorption layer is formed by coating light absorption paint with the thickness of 5mm on the outer surface of the glass cover, and the internal diffuse reflection layer is a diffuse reflection light reflection film arranged inside the glass cover and used for simulating the light state inside an eyeball.
The method for testing the visual angle of the fundus camera by using the testing device for the visual angle of the fundus camera comprises the following steps:
s1, determining the scale of a standard part scale through calculation, and displaying the standard part scale obtained through calculation on a display screen;
the specific method for determining the scale of the standard part scale through calculation comprises the following steps: because the average refractive index of the human eye 1.333 is different from the refractive index of air 1, the field angle β of the fundus camera in the human eye and the field angle α of the fundus camera in the air can be converted according to the following formula: α = (1.333/1) × β, that is, α =1.333 × β, and by projection, a circle corresponding to the corresponding visible angle is made on the plane, that is, the circle of the standard scale, and the circle radius r of the standard scale 2 = arctan(α/4)*2r 1 ，r 1 Radius of the human eye; human eye radius r for different people 1 Converting the radius r of the ring of the different standard scales 2 Shown as a set of concentric circles;
s2, fixing the fundus camera on a storage rack, enabling the center of a lens of the fundus camera and the circle center of a concentric circle on a standard component ruler to be on the same straight line, and turning on a strip-shaped LED light source;
s3, buckling the glass cover and a silica gel pad on the base, connecting an air pump with an air exhaust hole, opening the air pump, and exhausting air in the glass cover to form a vacuum environment;
s4, opening a scale of the standard component displayed by the fundus camera observation display screen, placing the fundus camera on a storage rack, aligning the lens center of the fundus camera to the circle center of the scale of the standard component, observing the visual range of imaging at a position 20mm away from the display screen, and directly reading the field angle beta of the fundus camera on human eyes on the scale of the standard component.
As for a specific method of determining the scale of the standard scale by calculation, the standard inner ring corresponding to the eye fundus camera at the angle of field β of the human eye of 130 ° in the present embodiment is an inner ring of the standard, which isThe field angle beta error of the middle fundus camera in human eyes is +/-5% (the inner circle of the standard part represents 123.5-136.5 degrees), the diameter of the human eyes is 20 mm: i.e. radius r 1 At 10mm, the field angle α =1.333 β =130 ° =173.29 ° of the fundus camera in air;
radius r of inner ring of standard part 2 =arctan(α/4)*2*r 1 =arctan(43.32°)*2*10=30.954mm。
The minimum error of field angle β =130 ° (1-5%) =123.5 ° corresponding to the inner circle of the standard, when the field angle α =1.333 × β =1.333 × 123.5 ° =164.63 ° of the fundus camera in air;
minimum radius error r of inner ring of standard part 2 ’ =arctan(α/4)*2*r 1 =arctan(41.16°)*2*10=30.930mm。
The maximum error of field angle β =130 ° (1 + 5%) =136.5 ° corresponding to the inner circle of the standard, when the field angle α =1.333 × β =1.333 × 136.5 ° =181.95 ° of the fundus camera in air;
maximum radius error of inner ring of standard part
r 2 ’‘ =arctan(α/4)*2*r 1 =arctan(45.49°)*2*10=30.976mm。
Example 2:
as for a specific method of determining the scale of the standard scale by calculation, in the present embodiment, calculation is performed as follows taking, as an example, a diameter of a human eye of 20mm when the angle of field β of the eye fundus camera is 140 ° as an eye:
the eyeground camera is a standard part middle ring corresponding to the condition that the field angle beta of the human eye is 140 degrees, wherein the error of the field angle beta of the eyeground camera on the human eye is +/-5 percent (the standard part middle ring represents 133-147 degrees), the diameter of the human eye is 20 mm: i.e. radius r 1 At 10mm, the field angle α =1.333 β =140 ° =186.62 ° of the fundus camera in air; radius r of middle ring of standard part 3 =arctan(α/4)*2*r 1 =arctan(46.66°)*2*10=30.988mm。
The minimum error of field angle corresponding to the standard piece middle circle β =140 ° (1-5%) =133 °, when the field angle α =1.333 × β =1.333 × 133 ° =177.29 ° of the fundus camera in air; minimum radius error r of middle ring of standard part 3 ’ =arctan(α/4)*2*r 1 =arctan(44.32°)*2*10=30.964mm。
The maximum error of field angle corresponding to the standard piece middle circle β =140 ° (1 + 5%) =147 when the field angle α =1.333 × β =1.333 × 147 ° =195.95 ° of the fundus camera in air;
maximum radius error of middle ring of standard part
r 3 ’‘ =arctan(α/4)*2*r 1 =arctan(48.99°)*2*10=31.008mm。
Example 3:
as for a specific method of determining the scale of the standard scale by calculation, in the present embodiment, calculation is performed as follows, taking an example of a diameter of 20mm of a human eye when the angle of view β of the fundus camera is 150 ° as an eye:
the eyeground camera is arranged on the outer circle of the standard part corresponding to the condition that the field angle beta of the human eye is 150 degrees, wherein the error of the field angle beta of the eyeground camera on the human eye is +/-5 percent (the outer circle of the standard part represents 142.5-157.5 degrees), the diameter of the human eye is 20 mm: i.e. radius r 1 At 10mm, the field angle α =1.333 β =150 ° =199.95 ° of the fundus camera in air; radius r of outer ring of standard component 4 =arctan(α/4)*2*r 1 =arctan(49.99°)*2*10=31.016mm。
The minimum error of the field angle corresponding to the circle on the outer circle of the standard component is beta =150 degrees (1-5%) =142.5 degrees, and the field angle alpha =1.333 degrees β =1.333 degrees 142.5 degrees= 189.95 degrees of the fundus camera in the air;
minimum radius error r of outer ring of standard component 4 ’ =arctan(α/4)*2*r 1 =arctan(47.49°)*2*10=30.994mm。
The maximum error of the field angle corresponding to the circle on the outer circle of the standard component is beta =150 degrees (1 + 5%) =157.5, and the field angle alpha =1.333 degrees beta =1.333 degrees 157.5 degrees= 209.95 degrees of the fundus camera in air;
maximum radius error of outer ring of standard part
r 4 ’‘ =arctan(α/4)*2*r 1 =arctan(52.49°)*2*10=31.034mm。
Comparative example:
as shown in FIG. 5, a view angle α is engraved with a photographing diameter of Φ =20mm using a 130 ° lens (lenses: ROP 130 degree unit) 1 An image of a graduated simulated eye;
the simulated eye is a transparent plastic ball with the diameter of 20mm, and the ball material is polymethyl methacrylate. The back half of the sphere is painted black. Along the black spherical surface, a corresponding graduated ring is carved at a position with a distance equivalent to a visual angle alpha measured from the center of an eyeball;
because the refractive index of human eyes (average 1.333) is different from the refractive index of the simulated eyes (1.489), the refraction angle generated after imaging light leaves the cornea (the spherical surface of the cornea of the simulated eyes) is different, and the angle measured in the simulated eyes is used for calculating the field angle of the human eyes and needs to be converted;
since the imaging light rays basically propagate along the radial direction of the corneal spherical surface, the incidence/refraction angle is relatively small, and the difference of the field angle in the human eyes can be calculated according to the ratio of the refractive indexes, namely, the refractive index of the simulated eyes is 1.489/1.333= 1.12; the method needs to manufacture the simulated eye according to the radius of the human eye, and the fundus camera with unknown field angle is used for measurement after the simulated eye is manufactured, so that time and labor are wasted, materials are wasted, and the operation is troublesome.
It should be noted that the above-mentioned contents only illustrate the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and it is obvious to those skilled in the art that several modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations fall within the protection scope of the claims of the present invention.

Claims (6)

1. The utility model provides a testing arrangement of fundus camera angle of vision, a serial communication port, be in including base and sealed setting glass cover on the base, the base bottom is provided with an aspirating hole that is used for connecting the aspiration pump, be provided with one on the base and arrange in the inside support of glass cover, be provided with a display screen that is used for showing the standard component scale on the base, connect the horizontal pole through mounting fixture on the support, install a supporter on the horizontal pole, supporter bottom is provided with can the pulley that removes on the horizontal pole, the pulley connect step motor, supporter bottom installation fundus camera.
2. The apparatus for testing field angle of a fundus camera according to claim 1, wherein a bar-shaped LED light source is disposed at the bottom of the cross bar, and the horizontal position of the bar-shaped LED light source is higher than the lens of the fundus camera.
3. The apparatus for testing the field angle of a fundus camera according to claim 1, wherein a laser range finder for measuring the distance from the bottom of the fundus camera to the display screen is provided on the fixture, and the laser range finder is mounted on the fixture by a slide rail.
4. The device for testing the field angle of a fundus camera according to claim 1, wherein the base is provided with a groove for placing a glass cover, a silica gel pad is arranged in the groove, the glass cover is tightly mounted on the silica gel pad, and the base is further provided with a bayonet for clamping the bracket.
5. The device for testing the field angle of an ophthalmoscopic camera according to claim 1, wherein the glass cover has a double-layer structure and comprises a diffuse reflection layer and a light absorption layer from inside to outside in sequence, the light absorption layer is formed by coating light absorption paint with the thickness of 5mm on the outer surface of the glass cover, and the internal diffuse reflection layer is a diffuse reflection light reflection film arranged inside the glass cover and used for simulating the light state inside an eyeball.
6. A method for testing the field angle of a fundus camera by using the device for testing the field angle of a fundus camera, which is characterized by comprising the following steps:
s1, determining the scale of a standard part scale through calculation, and displaying the standard part scale obtained through calculation on a display screen;
the specific method for determining the scale of the standard part scale through calculation comprises the following steps: due to the difference between the average refractive index of the human eye, 1.333, and the refractive index of air, 1The field angle beta of the fundus camera in human eyes and the field angle alpha of the fundus camera in air can be converted according to the following formula: α = (1.333/1) × β, that is, α =1.333 × β, and by projection, a circle corresponding to the corresponding visible angle is made on the plane, that is, the circle of the standard scale, and the circle radius r of the standard scale 2 = arctan(α/4)*2r 1 ，r 1 Radius of the human eye; human eye radius r for different people 1 Converting the radius r of the ring of the different standard scales 2 Shown as a set of concentric circles;
s2, fixing the fundus camera on a storage rack, enabling the center of a lens of the fundus camera and the circle center of a concentric circle on a standard component ruler to be on the same straight line, and turning on a strip-shaped LED light source;
s3, buckling the glass cover on a silica gel pad of the base, connecting an air pump with an air exhaust hole, opening the air pump, and exhausting air in the glass cover to form a vacuum environment;
s4, opening a scale of the standard component displayed on the eye fundus camera observation display screen, placing the eye fundus camera on a storage rack, aligning the center of a lens of the eye fundus camera to the circle center of the scale of the standard component, observing the visual range of imaging at a position 20mm away from the display screen, and directly reading the field angle beta of the eye fundus camera on human eyes on the scale of the standard component.
CN202210748820.3A 2022-06-29 2022-06-29 Device and method for testing field angle of fundus camera Pending CN115112354A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210748820.3A CN115112354A (en) 2022-06-29 2022-06-29 Device and method for testing field angle of fundus camera

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210748820.3A CN115112354A (en) 2022-06-29 2022-06-29 Device and method for testing field angle of fundus camera

Publications (1)

Publication Number Publication Date
CN115112354A true CN115112354A (en) 2022-09-27

Family

ID=83330078

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210748820.3A Pending CN115112354A (en) 2022-06-29 2022-06-29 Device and method for testing field angle of fundus camera

Country Status (1)

Country Link
CN (1) CN115112354A (en)

Similar Documents

Publication Publication Date Title
US8814356B2 (en) Physical model eye systems and methods
JP6301910B2 (en) Contact lens inspection apparatus and inspection method
CN109307480A (en) A kind of transmissive element multi-surface surface testing method
Applegate et al. How accurately can videokeratographic systems measure surface elevation?
Belin et al. Evaluating data acquisition and smoothing functions of currently available videokeratoscopes
CN1813624A (en) Strabism measuring instrument and its method for measuring strabism
Jagger The refractive structure and optical properties of the isolated crystalline lens of the cat
CN218546092U (en) Device for testing field angle of fundus camera
CN208876484U (en) For detecting and calibrating the tool of ophthalmology imaging, ophthalmology biological parameter measuring instrument
CN115112354A (en) Device and method for testing field angle of fundus camera
Fowler et al. Automatic measurement of varifocal spectacle lenses
US20220215584A1 (en) Apparatus for Calibrating Retinal Imaging Systems and Related Methods
CN114305318A (en) Numerical control eyeball protrusion measuring instrument and measuring method
CN209346993U (en) Diopter-adjustable debugs eye
Maurice An aplanation tonometer of new principle
Zhang et al. Metrological calibration of ophthalmometers
CN209299427U (en) A kind of novel FOV test device
CN109222886A (en) Diopter-adjustable debugs eye
Douthwaite et al. Surface tilt measured with the EyeSys videokeratoscope: influence on corneal asymmetry.
CN105549131B (en) A kind of serial Test lenses for being used to examine contact lense geometric parameter measurement instrument
Holden An accurate and reliable method of measuring soft contact lens curvatures
Fowler et al. Varifocal spectacle lens surface power measurement
CN218943309U (en) Novel eyeball salience measuring instrument
US1953738A (en) Eye testing instrument
CN1126580A (en) Standard model eye for subjective optometer

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination