LINK ARK-7800

Hospital ophthalmology departments and NHS eye clinic units managing populations with extreme refractive error benefit most directly from the ARK-7800's -30.00D to +25.00D sphere range, which covers presentations that cannot be measured on the ±20D instruments in the ARK range. High myopia clinics, paediatric myopia management services, post-refractive surgery services managing over-corrected or under-corrected outcomes, and high hyperopia services for children and adults all encounter sphere values outside the ±20D limit — the ARK-7800 addresses these measurement gaps within the same instrument used for the standard refractive population. For NHS trusts and institutional procurement managers, the SHARP-branded 7-inch TFT LCD monitor, AC 100 to 250V universal power supply, and auto paper-cutting printer contribute to the unit's suitability for high-volume clinical examination environments. Medigear.uk provides procurement documentation and pre-purchase consultation for ophthalmology units evaluating the ARK-7800.

Optometry practices and optical dispensaries serving populations with keratoconus, high myopia, post-LASIK or post-LASEK patients, and other high or unusual refractive presentations benefit from the ARK-7800's broad sphere and corneal measurement capability — including 0.00D to 15.00D corneal astigmatism and 5.0 to 10.0mm corneal curvature — within a single automated measurement sequence. The motorised chin rest, auto-tracking and focusing during measurement, and SHARP 7-inch TFT LCD with front-and-back adjustment support efficient and ergonomic operation across diverse patient presentations. Medigear.uk supplies the ARK-7800 to optometry practices and equipment distributors through its B2B procurement channel.

Specialist refractive surgery centres and keratoconus management units benefit from the ARK-7800's combination of extreme sphere range and broad corneal astigmatism measurement within the same automated measurement workflow. The Hartman imaging technology provides consistent results across irregular corneal presentations.

Individual buyers and private clinics with high-prescription patient populations can acquire the ARK-7800 directly through Medigear.uk.

Widest Sphere Range in the ARK Series: 30.00D to +25.00D

The ARK-7800 measures sphere from -30.00D to +25.00D — the broadest range in the ARK instrument series and the defining capability that distinguishes the ARK-7800 from all other ARK models available from Medigear.uk. Where the ARK-980, ARK-1500, ARK-1800, ARK-4000, and ARK-4000A all measure sphere to ±20D, the ARK-7800 extends 10D further into high myopia and 5D further into high hyperopia, covering extreme refractive presentations that would otherwise require subjective-only assessment. This makes the ARK-7800 the appropriate ARK instrument choice for any service that routinely encounters patients with sphere below -20D or above +20D.

Hartman Imaging Technology for Consistent High-Range Accuracy

Hartman imaging analysing and processing technology delivers accurate measurement results through a new optical system with a unique imaging impression, providing reliable refractometry across the ARK-7800's full -30.00D to +25.00D sphere range. High myopia and high hyperopia present different optical challenges for auto refractometer systems than standard refractive populations — the ARK-7800's specifically adapted light path and Hartman imaging architecture are developed to maintain measurement accuracy at the extremes of its measurement range as well as in the standard range. Medigear.uk can provide full optical system documentation on request.

Motorised Chin Rest for Automated Patient Positioning

The motorised chin rest automatically adjusts patient height in coordination with the auto tracking and focusing system, reducing the manual positioning effort between patients and ensuring consistent eye alignment relative to the instrument's optical axis. For high-volume examination sessions serving a diverse refractive population, including high-prescription patients who may have limited comfortable head positioning range, automated chin rest adjustment reduces the physical demands on both operator and patient during the measurement sequence.

Auto Tracking and Focusing During Measuring

The ARK-7800's auto tracking and focusing function operates continuously during the measurement sequence, compensating for small patient eye movements and maintaining optical alignment through the under-0.5-second measurement cycle without requiring manual re-trigger or repositioning. This continuous tracking is particularly valuable for high refractive error patients, who may find fixation more challenging than emmetropic patients and who may present with higher nystagmus or fixation instability due to long-standing extreme refractive error.

SHARP 7-inch TFT LCD with Front-and-Back Movement

The SHARP 7-inch TFT LCD touch screen moves front and back freely, allowing the operator to adjust the display distance for their viewing comfort at any desk depth — a different ergonomic adjustment axis from the up-and-down rotation on the ARK-4000 series and the tilting on the ARK-1500. The SHARP brand designation confirms a named, quality display component. The 7-inch touch screen size provides clear result display and confident touch navigation without a separate keyboard.

Cylinder to 10.00D for High Astigmatism Alongside High Sphere

The ARK-7800's cylinder range of 0.00D to +10.00D is the same as the ARK-4000 and significantly broader than the 6.00D on the ARK-4000A, supporting measurement of high astigmatism that co-presents with extreme sphere values in many high-prescription patients. This cylinder range ensures the ARK-7800's extended sphere capability is not limited by an insufficient cylinder upper bound for the high-prescription populations it is designed to serve.

Corneal Astigmatism to 15.00D for Specialist Keratometry

The ARK-7800 measures corneal astigmatism from 0.00D to 15.00D, matching the ARK-4000 and significantly exceeding the 8.00D limit on the ARK-1500 and ARK-1800. This 15.00D range covers advanced keratoconus, post-keratoplasty irregular astigmatism, and corneal ectasia presentations that frequently co-exist with high myopia in the patient populations for which the ARK-7800's sphere range is specifically designed. The 5.0 to 10.0mm corneal curvature radius range matches the ARK-4000's broad keratometry coverage.

Universal 100–250V for Flexible Deployment

The ARK-7800 operates on AC 100 to 250V at 50/60Hz, providing universal voltage compatibility for deployment across all NHS trust sites, international clinical environments, and distributor supply territories without transformer conversion.

Sphere: 30.00D to +25.00D — Broadest in the ARK Series

The ARK-7800 measures sphere from -30.00D to +25.00D at VD=12mm in four selectable steps: 0.01D, 0.06D, 0.12D, or 0.25D. This is the widest sphere range in the ARK instrument series, extending 10D beyond the -20D lower limit and 5D beyond the +20D upper limit of all other ARK models.

Cylinder: 0.00D to +10.00D

Cylinder spans 0.00D to +10.00D in 0.06D, 0.12D, or 0.25D units, covering high astigmatism co-presenting with extreme sphere values. Cylinder form is selectable as minus, plus, or combined.

Axis: 1° to 180°, 1° Unit

Axis covers 1° to 180° in 1° steps for both refraction and keratometry.

Vertex Distance: Four Options

Four vertex distance options — 0.0mm, 12.0mm, 13.75mm, and 15.0mm — match the ARK-4000 and ARK-4000A, covering all standard spectacle frame vertex distances.

Pupil Distance: 10 to 86mm

Pupil distance spans 10 to 86mm covering all adult and paediatric monocular PD requirements.

Measurement Time: Under 0.5 Seconds

Measurement completes in under 0.5 seconds, enabled by Hartman imaging optics, auto tracking, and auto focusing during measurement.

Cornea Curvature Radius: 5.0 to 10.0mm, 0.01 mm unit

Corneal curvature radius spans 5.0 to 10.0mm in 0.01mm units, covering steep keratoconic through to flat post-refractive surgery corneas.

Corneal Power: 33.00D to 67.00D, Equivalent 1.3376

Corneal power spans 33.00 to 67.00D based on corneal equivalent refractive power of 1.3376, covering the full clinically relevant keratometry range.

Corneal Astigmatism: 0.00D to 15.00D

Corneal astigmatism spans 0.00 to 15.00D in 0.06D, 0.12D, or 0.25D units, supporting advanced keratoconus and high irregular astigmatism measurement.

Monitor: SHARP 7-inch TFT LCD, Front-and-Back Movement.

SHARP-branded 7-inch TFT LCD touch screen with adjustable viewing angle that moves front and back freely for ergonomic display distance adjustment.

Motorised Chin Rest

Automatic motorised chin rest adjustment supports efficient patient positioning and consistent eye alignment without manual height setting between patients.

Auto Tracking and Focusing During Measuring

Continuous auto tracking and focusing during the measurement sequence compensates for patient eye movement, maintaining measurement accuracy through the sub-0.5-second cycle.

Power Supply: AC 100 to 250V, 50/60Hz

Universal power supply compatible with all international electrical standards. Net weight: 22 kg, gross 26.5kg. Packing size confirmed through Medigear.uk.

The ARK-7800 auto refractometer keratometer provides a validated, full-function refraction and keratometry platform suited to hospital ophthalmology departments, NHS eye clinics, optometry practices, and specialist ophthalmic suites managing high and extreme refractive error populations. Its broadest-in-class sphere range from 30.00D to 25.00D, Hartman imaging technology, SHARP 7-inch TFT LCD with front-and-back movement, motorised chin rest, auto-tracking and focusing during measurement, corneal astigmatism to 15D, cylinder to 10D, and universal 100 to 250V power supply collectively address the requirements of institutional procurement teams, independent practice owners, and specialist distributors. Full documentation is available from Medigear.uk. Contact Medigear.uk for specifications, procurement assistance, or expert consultation.