ARK-1 Series Autorefractor/Keratometers
Three autorefractor/keratometers, one optical platform
The ARK-1 series covers three instruments (the ARK-1s, ARK-1a and ARK-1) sharing a Super Luminescent Diode light source that produces sharper images than LED and, importantly, reads accurately through many cataracts. They differ mainly in tracking sophistication and features: the 1s and 1a offer full X-Y-Z eye tracking, the ARK-1 offers Y tracking.
What it does
- Super Luminescent Diode source for sharper images than LED
- Accurate data through many cataracts
- X-Y-Z eye tracking on the ARK-1s and ARK-1a; Y tracking on the ARK-1
- Large pupil zone imaging method up to 6 mm diameter
- Keratometry with mire ring to reduce eyelid artifact
- Accommodation measurement on the ARK-1s and ARK-1a
- 6.5-inch full-color LCD screen
Is it right for your practice?
Best fit
Any practice doing pre-test, and particularly practices with an older patient population where media opacity makes autorefraction unreliable.
Why consider it
The cataract point is the one that matters clinically. An autorefractor that gives you nothing on a patient with significant lens changes has failed at exactly the moment you needed it, and the Super Luminescent Diode source is what makes readings possible through many cataracts. Keratometry uses a mire ring to reduce eyelid artifact, imaging covers a pupil zone up to 6 mm, and the series feeds the TRS refractors and the EPIC workstation directly, which removes transcription from pre-test.
What to compare
Within the series the practical difference is tracking and accommodation measurement: the 1s and 1a have full X-Y-Z tracking and accommodation measurement, the ARK-1 has Y tracking and does not. If your technicians are experienced and your volume is moderate, the ARK-1 is enough and the extra tracking is capability you are paying for twice. If you want the instrument to do more of the alignment work, the ARK-F takes that further than any of the three. And if counter space is your problem and not accuracy, the Tonoref II folds tonometry into the same footprint.
Ask me about
Which model your technicians would get the most from, and whether your EMR takes the data directly or needs a bridge.
Specifications
These are the published figures for the 1S. The other models in this family differ; ask me for the specification sheet on the one you are considering.
| Objective Spherical Refractive Error | -30.00 to +25.00 D (VD = 12 mm) (0.01/0.12/0.25 D increments) |
|---|---|
| Cylindrical Refractive Error (Technical Details) | 0 to ±12.00 D (0.01/0.12/0.25 D increments) |
| Cylinder Axis | 0 to 180° (1°/5° increments) |
| Minimum Measurable Pupil Diameter | ø2 mm |
| Subjective Visual Acuity Measurements | <0.1 / 0.1 / 0.25 / 0.32 / 0.4 / 0.5 / 0.63 / 0.8 / 1.0 / 1.25 <20/200 / 20/200 / 20/80 / 20/60 / 20/50 / 20/40 / 20/30 / 20/25 / 20/20 / 20/16 |
| Spherical Refractive Error | -20.00 to +20.00 D (VD = 12 mm) (0.25 D increments) |
| Near Addition Power | 0 to +9.75 D (0.25 D increments) |
| Corneal Curvature Radius | 5.00 to 13.00 mm (0.01 mm increments) |
| Corneal Refractive Power | 25.96 to 67.50 D (n = 1.3375) (0.01/0.12/0.25 D increments) |
| Corneal Cylindrical Power | 0 to ±12.00 D (0.01/0.12/0.25 D increments) |
| Corneal Cylinder Axis | 0 to 180° (1°/5° increments) |
| Pupillary Distance Measurement | 30 to 85 mm (1 mm increments) |
| Corneal Size Measurement | 10.0 to 14.0 mm (0.1 mm increments)Fixation TargetN/A |
| Pupil Size Measurement | 1.0 to 10.0 mm (0.1 mm increments) |
| Accomodation Measurement | 0 to 10.00 D (0.01/0.12/0.25 D increments) |
| Observation/Display Method | 6.5-inch color LCD |
| Printer | Thermal line printer with auto cutter |
| Interface Connectors | RS-232C: Two ports USB: One port LAN: One port |
| Power Supply | AC 100 to 240 V ±10% 50/60 Hz |
| Power Consumption | 100 VA |
| Measurements | 260 (W) mm / 495 (D) mm / 457 (H) mm |
| Mass | 20 kg |
Worth comparing
ARK-F Autorefractor/Keratometer
A fully automatic autorefractor/keratometer with voice command guidance for both staff and patient.
Tonoref II ARK with Tonometry
Autorefractor, keratometer and non-contact tonometer in a single instrument, for pretest rooms short on floor space.
OPD-Scan III Wavefront Aberrometer
Autorefractor, keratometer, pupillometer, corneal topographer and wavefront aberrometer in one instrument, capturing over 20 diagnostic measurements in roughly ten seconds per eye.
Specifications reviewed: 2026-09-06
Manufacturer source:
Marco: ARK-1 Series Autorefractor/Keratometers.
Configurations and specifications change. Ask me to confirm before ordering.
Talk it through with me
Tell me how your practice handles this now and what you want it to do, and we can work through the options together. You do not need to have settled on a product first.