ARK-1/AR-1 Series Specifications

Model
Auto refractometer
ARK-1s/AR-1s ARK-1a/AR-1a ARK-1/AR-1 Auto Ref/Keratometer ARK-1s/1a/1
AR-1s/1a/1
Measurement range Sphere -30.00 to +25.00 D (VD = 12 mm)
(0.01/0.12/0.25 D increments)
Cylinder 0 to ±12.00 D (0.01/0.12/0.25 D increments) Auto Refractometer
Axis 0 to 180° (1°/5° increments)
Minimum measurable pupil diameter ø2 mm
Auto keratometer*1
Measurement range Curvature radius 5.00 to 13.00 mm
(0.01 mm increments)
Refractive power 25.96 to 67.50 D (n = 1.3375)
(0.01/0.12/0.25 D increments)
Cylindrical power 0 to ±12.00 D
(0.01/0.12/0.25 D increments)
Axis 0 to 180º (1°/5° increments)
Sagittal measurement 25º each from the center
(superior side, inferior side, temporal side, nasal side)
VA measurement
Measurement mode Uncorrected VA, Corrected VA (distance, near)
Measurement range Less than 0.1, 0.1, 0.25, 0.32, 0.4, 0.5, 0.63, 0.8, 1.0, 1.25 or
Less than 20/200, 20/200, 20/80, 20/60, 20/50,
20/40, 20/30, 20/25, 20/20, 20/16 Not available Not available
Correction range Sphere -20.00 to +20.00 D (VD = 12 mm)
(0.25 D increments)
Cylinder 0 to ±8.00 D (0.25 D increments)
Axis 0 to 180º (1º/5º increments)
Vision comparison Available with VA chart Available with scenery chart Available*2 / Not available*3
Retroillumination image Available Not available
Accommodation measurement range 0 to 10.00 D (0.01/0.12/0.25 D increments) Not available
Pupillary distance measurement range 30 to 85 mm (1 mm increments)
(Near point PD: 28 to 80 mm at WD = 40 cm)
Corneal size measurement range*1 10.0 to 14.0 mm (0.1 mm increments)
Pupil size measurement range 1.0 to 10.0 mm (0.1 mm increments)
Auto tracking X-Y-Z directions Y direction
Auto shot Available
Display Tiltable 6.5-inch color LCD
Printer Thermal line printer with easy loading and auto cutter
Interface RS-232C: 2 ports
USB, LAN: 1 port each
Power supply 100 to 240 V AC, 50/60 Hz
Power consumption 100 VA
Dimensions/mass 260 (W) x 495 (D) x 457 (H) mm / 20 kg
10.2 (W) x 19.5 (D) x 18.0 (H)" / 44 lbs.
Standard accessories Printer paper, Power cord, Dust cover, Chinrest paper,
Fixing pins for chinrest paper, Spherical model eye with
integrated contact lens holder*4
Optional accessories Eye Care card,Communication cable (RS-232C)

*1 Available for the ARK-1s, ARK-1a, and ARK-1

*2 Available with scenery chart for the ARK-1
*3 Not available for the AR-1
*4 The integrated contact lens holder is used only with the ARK-1s, ARK-1a, and ARK-1.

Product/model name: AUTO REF/KERATOMETER ARK-1/ARK-1a/ARK-1s

AUTO REFRACTOMETER AR-1/AR-1a/AR-1s
Brochure and listed features of the device are intended for non-US practitioners.
The availability of products differs from country to country depending on the status of approval.
Specifications may vary depending on circumstances in each country.
Specifications and design are subject to change without notice.

HEAD OFFICE [Manufacturer] Distributor in your country

34-14 Maehama, Hiroishi-cho, Gamagori, Aichi 443-0038, JAPAN Please contact our distributor
Phone: +81-533-67-8895 for more information.
Group Website www.nidek.com www.nidek-intl.com/dist/
Product Information www.nidek-intl.com/product/

ARK-1/AR-1_B01E009
The Superior Auto Ref/Keratometer
and Auto Refractometer
What is the superior auto ref/keratometer and auto refractometer?
The ARK-1/AR-1 series speaks for itself, surpassing conventional auto ref/keratometer
and auto refractometer with technologically enhanced functions
generating greater accuracy and greater clinical information.

Superior Functions for Superior Outcomes

Accurate Refraction Measurement Easy VA Measurement with Glare Test
Simple Opacity Assessment Patient-friendly Accommodation Measurement

Fog under
VA Vision Accommodation Opacity Auto
Model Glare test astigmatism
measurement comparison measurement assessment tracking
correction
ARK-1s/AR-1s X-Y-Z directions
ARK-1a/AR-1a X-Y-Z directions
ARK-1/AR-1 * Y direction
: Available, : Not available
*Available with scenery chart for the ARK-1
Not available for the AR-1
The Superior Auto Ref/Keratometer
and Auto Refractometer
What is the superior auto ref/keratometer and auto refractometer?
The ARK-1/AR-1 series speaks for itself, surpassing conventional auto ref/keratometer
and auto refractometer with technologically enhanced functions
generating greater accuracy and greater clinical information.

Superior Functions for Superior Outcomes

Accurate Refraction Measurement Easy VA Measurement with Glare Test
Simple Opacity Assessment Patient-friendly Accommodation Measurement

Fog under
VA Vision Accommodation Opacity Auto
Model Glare test astigmatism
measurement comparison measurement assessment tracking
correction
ARK-1s/AR-1s X-Y-Z directions
ARK-1a/AR-1a X-Y-Z directions
ARK-1/AR-1 * Y direction
: Available, : Not available
* Available with scenery chart for the ARK-1
Not available for the AR-1
 Accurate Refraction Measurement Easy VA Measurement with Glare Test

Large pupil zone imaging method VA measurement with built-in charts and lenses (available for the ARK-1s and AR-1s)
The large pupil zone imaging method enables the measurement of wider area refraction up to 6 mm diameter and can The ARK-1s and AR-1s provides visual acuity (VA) measurement. This unique function enables a quick check of the
indicate the difference between the wide area refraction and central area refraction of up to 3.5 mm diameter. These patient's refractive error by comparing subjective measurement with objective measurement. Even corrected near visual
pupil diameters are measured simultaneously. The difference of the measurement allows assessment of the effect of acuity is measurable with easy operability to determine the need for a progressive lens.
pupil size such as a vision in dim light.
Central area: ø1 to 3.5 mm area
Central area: ø1 to 4 mm area Recall function for instant vision comparisons (available for the ARK-1s/1a/1 and AR-1s/1a)
Large area: ø1 to 6 mm area
The recall function provides the instant comparison between vision corrected with AR
data and uncorrected vision or vision corrected with the data of patient’s own glasses.
For the patient, this function demonstrates the difference in vision and the necessity
for more appropriate vision correction.

Uncorrected distance vision

Ring image Ring image Distance vision corrected with AR data
Distance vision corrected with LM data*
Uncorrected near vision
ARK-500/AR-300 series ARK-1/AR-1 series Near vision corrected with AR data
Pupil zone imaging method Large pupil zone imaging method Near vision corrected with LM data*
*The data of patient’s own glasses has to be imported
Vision comparisons from a NIDEK lensmeter.

Contrast and glare test (available for the ARK-1s and AR-1s)
Super luminescent diode and highly sensitive CCD After a low contrast VA chart is
presented, a glare source is illuminated
Incorporation of the super luminescent diode (SLD) provides a sharper and clearer image compared to a conventional
beside the chart and the glare VA can
LED. The highly sensitive CCD detects the ring image even if the fundus reflection is weak. The system, which combines
be measured. With this test the effect
the SLD and highly sensitive CCD, significantly improves measurement capability even in dense cataractous eyes.
of glare and halo to visual performance
can be measured. This utility can be
used for cataract and refractive surgery Simulated patient’s vision of Vision with glare and halo Normal vision
patients. low contrast VA chart Simulated patient’s vision of VA chart and glare source

Half
Eye mirror
SLD (normal eye) LED (normal eye)
Ring lens

Reflective Keratometry Measurement with Mire Ring (available for the ARK-1s/1a/1)
mirror
Highly The mire ring is used to measure keratometry. It reduces eyelid artifacts.
SLD sensitive Hyperopia Emmetropia Myopia
CCD

Astigmatism Astigmatism SLD (cataractous eye)* LED (cataractous eye)*

Simulated ring image Captured ring image
Emitted SLD light Reflected light Ring image
*In-house data of a cataractous model eye

Optimal fogging to minimize accommodation (available for the ARK-1s/1a and AR-1s/1a) Measurement with mire ring
Fogging is performed after correcting the patient’s astigmatism with built-in cylinder lenses. This allows the patient
to view the target clearly and minimizes the interference with accommodation even in high astigmatism.
 Accurate Refraction Measurement Easy VA Measurement with Glare Test

Large pupil zone imaging method VA measurement with built-in charts and lenses (available for the ARK-1s and AR-1s)
The large pupil zone imaging method enables the measurement of wider area refraction up to 6 mm diameter and can The ARK-1s and AR-1s provide visual acuity (VA) measurement. This unique function enables a quick check of the
indicate the difference between the wide area refraction and central area refraction of up to 3.5 mm diameter. These patient's refractive error by comparing subjective measurement with objective measurement. Even corrected near visual
pupil diameters are measured simultaneously. The difference of the measurement allows assessment of the effect of acuity is measurable with easy operability to determine the need for a progressive lens.
pupil size such as a vision in dim light.
Central area: ø1 to 3.5 mm area
Central area: ø1 to 4 mm area Recall function for instant vision comparisons (available for the ARK-1s/1a/1 and AR-1s/1a)
Large area: ø1 to 6 mm area
The recall function provides the instant comparison between vision corrected with AR
data and uncorrected vision or vision corrected with the data of patient’s own glasses.
For the patient, this function demonstrates the difference in vision and the necessity
for more appropriate vision correction.

Uncorrected distance vision

Ring image Ring image Distance vision corrected with AR data
Distance vision corrected with LM data*
Uncorrected near vision
ARK-500/AR-300 series ARK-1/AR-1 series Near vision corrected with AR data
Pupil zone imaging method Large pupil zone imaging method Near vision corrected with LM data*
*The data of patient’s own glasses has to be imported
Vision comparisons from a NIDEK lensmeter.

Contrast and glare test (available for the ARK-1s and AR-1s)
Super luminescent diode and highly sensitive CCD After a low contrast VA chart is
presented, a glare source is illuminated
Incorporation of the super luminescent diode (SLD) provides a sharper and clearer image compared to a conventional
beside the chart and the glare VA can
LED. The highly sensitive CCD detects the ring image even if the fundus reflection is weak. The system, which combines
be measured. With this test the effect
the SLD and highly sensitive CCD, significantly improves measurement capability even in dense cataractous eyes.
of glare and halo to visual performance
can be measured. This utility can be
used for cataract and refractive surgery Simulated patient’s vision of Vision with glare and halo Normal vision
patients. low contrast VA chart Simulated patient’s vision of VA chart and glare source

Half
Eye mirror
SLD (normal eye) LED (normal eye)
Ring lens

Reflective Keratometry Measurement with Mire Ring (available for the ARK-1s/1a/1)
mirror
Highly The mire ring is used to measure keratometry. It reduces eyelid artifacts.
SLD sensitive Hyperopia Emmetropia Myopia
CCD

Astigmatism Astigmatism SLD (cataractous eye)* LED (cataractous eye)*

Simulated ring image Captured ring image
Emitted SLD light Reflected light Ring image
*In-house data of a cataractous model eye

Optimal fogging to minimize accommodation (available for the ARK-1s/1a and AR-1s/1a) Measurement with mire ring
Fogging is performed after correcting the patient’s astigmatism with built-in cylinder lenses. This allows the patient
to view the target clearly and minimizes the interference with accommodation even in high astigmatism.
 Patient-friendly Accommodation Measurement Practical and User-friendly Features
(available for the ARK-1s/1a and AR-1s/1a)

Accommodation measurement with intelligence algorithm

Objective measurement of accommodation is performed with the patient focusing Amplitude of 3D* auto tracking and Tiltable color LCD screen High-speed printer with
on a target that moves from distance to near. Intelligence algorithm detects the
accommodation auto shot easy loading and auto cutter
patient response and reduces the measurement time in cases with a slow or weak The 3D auto tracking and auto The color LCD with tilt function The printer paper can be
Accommodation
accommodative response. The accommodation measurement helps to assess graph shot provide faster, simpler, and offers easy operation even when changed easily. The data sheet is
pseudomyopia, eyestrain, and accommodative palsy. more accurate measurements. the operator is standing. cut by an auto cutter for quick
Pupil diameter graph When alignment is performed and easy detachment.
correctly, measurement starts
Measurement with astigmatism correction
automatically. Y direction

Astigmatism is corrected with built-in cylinder lenses *Y direction (vertical)

14 X direction
prior to measurement. It reduces the influence of auto tracking is FOCUS
accommodation (D)

12 available for the

astigmatism on the measurement of accommodation.
Amplitude of

10 ARK-1 and AR-1.

8
6
4
Assessment for intermediate or near vision lens
2
The assessment of accommodation based on the 0
0 10 20 30 40 50 60 70 80
age-accommodation relation allows to suggest whether Age (year)
an intermediate or near lens is required. Courtesy of Masayoshi Kajita, MD, PhD
The amplitudes of accommodation on the graph are values of subjective measurement.
The amplitudes of accommodation of objective measurement tend to be lower than
those on the graph. Summary display and printout of Quick and easy data transfer
measured values
Various measured values can be displayed The ARK-1/AR-1 series has simple interfaces such as
Simple Opacity Assessment simultaneously on the summary screen allowing easy LAN and RS-232C for seamless data communication
(available for the ARK-1s/1a and AR-1s/1a) and quick confirmation and printing. with multiple devices. An optional Eye Care card is
also available for wireless data transfer to enhance
Retroillumination image and NIDEK cataract indices productivity.

The retroillumination image enables the observation of opacity of the optical media
of the eye. NIDEK cataract indices indicate the severity of the opacity and help to
assess the progression of pathology.

Intelligent Auto
COI.H Opacity size within a diameter of 3 mm of the center (vertical diameter): mm Refractor Lensmeter

COI.A Opacity proportion within a diameter of 3 mm of the center: % Eye with dense opacity

POI Opacity proportion within the entire periphery: %

Cataract indices

The NIDEK cataract indices are for reference only.

The following conditions may indicate different indices from ones of actual status.
Peripheral image is darkly captured due to alignment position.
Opacities are not in focus.
Bright spot reflecting observation light occurs on the cornea apex.
Position of the 3 mm diameter circle is shifted due to incorrect pupil detection caused by opacity location.

Eye with light opacity

 Patient-friendly Accommodation Measurement Practical and User-friendly Features
(available for the ARK-1s/1a and AR-1s/1a)

Accommodation measurement with intelligence algorithm

Objective measurement of accommodation is performed with the patient focusing Amplitude of 3D* auto tracking and Tiltable color LCD screen High-speed printer with
on a target that moves from distance to near. Intelligence algorithm detects the
accommodation auto shot easy loading and auto cutter
patient response and reduces the measurement time in cases with a slow or weak The 3D auto tracking and auto The color LCD with tilt function The printer paper can be
Accommodation
accommodative response. The accommodation measurement helps to assess graph shot provide faster, simpler, and offers easy operation even when changed easily. The data sheet is
pseudomyopia, eyestrain, and accommodative palsy. more accurate measurements. the operator is standing. cut by an auto cutter for quick
Pupil diameter graph When alignment is performed and easy detachment.
correctly, measurement starts
Measurement with astigmatism correction
automatically. Y direction

Astigmatism is corrected with built-in cylinder lenses *Y direction (vertical)

14 X direction
prior to measurement. It reduces the influence of auto tracking is FOCUS
accommodation (D)

12 available for the

astigmatism on the measurement of accommodation.
Amplitude of

10 ARK-1 and AR-1.

8
6
4
Assessment for intermediate or near vision lens
2
The assessment of accommodation based on the 0
0 10 20 30 40 50 60 70 80
age-accommodation relation allows to suggest whether Age (year)
an intermediate or near lens is required. Courtesy of Masayoshi Kajita, MD, PhD
The amplitudes of accommodation on the graph are values of subjective measurement.
The amplitudes of accommodation of objective measurement tend to be lower than
those on the graph. Summary display and printout of Quick and easy data transfer
measured values
Various measured values can be displayed The ARK-1/AR-1 series has simple interfaces such as
Simple Opacity Assessment simultaneously on the summary screen allowing easy LAN and RS-232C for seamless data communication
(available for the ARK-1s/1a and AR-1s/1a) and quick confirmation and printing. with multiple devices. An optional Eye Care card is
also available for wireless data transfer to enhance
Retroillumination image and NIDEK cataract indices productivity.

The retroillumination image enables the observation of opacity of the optical media
of the eye. NIDEK cataract indices indicate the severity of the opacity and help to
assess the progression of pathology.

Intelligent Auto
COI.H Opacity size within a diameter of 3 mm of the center (vertical diameter): mm Refractor Lensmeter

COI.A Opacity proportion within a diameter of 3 mm of the center: % Eye with dense opacity

POI Opacity proportion within the entire periphery: %

Cataract indices

The NIDEK cataract indices are for reference only.

The following conditions may indicate different indices from ones of actual status.
Peripheral image is darkly captured due to alignment position.
Opacities are not in focus.
Bright spot reflecting observation light occurs on the cornea apex.
Position of the 3 mm diameter circle is shifted due to incorrect pupil detection caused by opacity location.

Eye with light opacity

ARK-1/AR-1 Series Specifications
Model
Auto refractometer
ARK-1s/AR-1s ARK-1a/AR-1a ARK-1/AR-1 Auto Ref/Keratometer ARK-1s/1a/1
AR-1s/1a/1
Measurement range Sphere -30.00 to +25.00 D (VD = 12 mm)
(0.01/0.12/0.25 D increments)
Cylinder 0 to ±12.00 D (0.01/0.12/0.25 D increments) Auto Refractometer
Axis 0 to 180° (1°/5° increments)
Minimum measurable pupil diameter ø2 mm
Auto keratometer*1
Measurement range Curvature radius 5.00 to 13.00 mm
(0.01 mm increments)
Refractive power 25.96 to 67.50 D (n = 1.3375)
(0.01/0.12/0.25 D increments)
Cylindrical power 0 to ±12.00 D
(0.01/0.12/0.25 D increments)
Axis 0 to 180º (1°/5° increments)
Sagittal measurement 25º each from the center
(superior side, inferior side, temporal side, nasal side)
VA measurement
Measurement mode Uncorrected VA, Corrected VA (distance, near)
Measurement range Less than 0.1, 0.1, 0.25, 0.32, 0.4, 0.5, 0.63, 0.8, 1.0, 1.25 or
Less than 20/200, 20/200, 20/80, 20/60, 20/50,
20/40, 20/30, 20/25, 20/20, 20/16 Not available Not available
Correction range Sphere -20.00 to +20.00 D (VD = 12 mm)
(0.25 D increments)
Cylinder 0 to ±8.00 D (0.25 D increments)
Axis 0 to 180º (1º/5º increments)
Vision comparison Available with VA chart Available with scenery chart Available*2 / Not available*3
Retroillumination image Available Not available
Accommodation measurement range 0 to 10.00 D (0.01/0.12/0.25 D increments) Not available
Pupillary distance measurement range 30 to 85 mm (1 mm increments)
(Near point PD: 28 to 80 mm at WD = 40 cm)
Corneal size measurement range*1 10.0 to 14.0 mm (0.1 mm increments)
Pupil size measurement range 1.0 to 10.0 mm (0.1 mm increments)
Auto tracking X-Y-Z directions Y direction
Auto shot Available
Display Tiltable 6.5-inch color LCD
Printer Thermal line printer with easy loading and auto cutter
Interface RS-232C: 2 ports
USB, LAN: 1 port each
Power supply 100 to 240 V AC, 50/60 Hz
Power consumption 100 VA
Dimensions/mass 260 (W) x 495 (D) x 457 (H) mm / 20 kg
10.2 (W) x 19.5 (D) x 18.0 (H)" / 44 lbs.
Standard accessories Printer paper, Power cord, Dust cover, Chinrest paper,
Fixing pins for chinrest paper, Spherical model eye with
integrated contact lens holder*4
Optional accessories Eye Care card, Communication cable (RS-232C)

*1 Available for the ARK-1s, ARK-1a, and ARK-1

*2 Available with scenery chart for the ARK-1
*3 Not available for the AR-1
*4 The integrated contact lens holder is used only with the ARK-1s, ARK-1a, and ARK-1.

Product/model name: AUTO REF/KERATOMETER ARK-1/ARK-1a/ARK-1s

AUTO REFRACTOMETER AR-1/AR-1a/AR-1s
Brochure and listed features of the device are intended for non-US practitioners.
The availability of products differs from country to country depending on the status of approval.
Specifications may vary depending on circumstances in each country.
Specifications and design are subject to change without notice.

HEAD OFFICE [Manufacturer] Distributor in your country

34-14 Maehama, Hiroishi-cho, Gamagori, Aichi 443-0038, JAPAN Please contact our distributor
Phone: +81-533-67-8895 for more information.
Group Website www.nidek.com www.nidek-intl.com/dist/
Product Information www.nidek-intl.com/product/

ARK-1/AR-1_B01E009