LINK VT-20

Reaches prescriptions that stop most refracting heads

The LINK VT-20 is an extended range phoropter that carries spherical testing to plus 26.75D and minus 29.00D when the optional plus or minus 10.00D lens is used. Interpupillary adjustment reaches down to 48mm, and rotary prism covers 20 prism dioptres in single steps.

Sections

Phoropters

High Power and Post-Surgical Prescriptions

The optional plus or minus 10.00D lens extends spherical testing to plus 26.75D and minus 29.00D. Aphakic patients, high myopes and those left with substantial residual error after ocular surgery can be refracted properly at the head rather than through improvised trial frame combinations. Working within a single instrument keeps vertex distance consistent throughout the examination, which matters a great deal at powers this high, where small positional differences change the effective correction reaching the eye.

Paediatric and Narrow Interpupillary Testing

Interpupillary adjustment from 48mm accommodates children and adults whose interpupillary distance sits below what many refracting heads reach. Where the setting cannot be brought narrow enough, the patient looks through the lenses off centre, introducing unwanted prism and undermining the whole refraction. Practices seeing children regularly, or working in school screening programmes, benefit directly from the wider adjustment span.

Routine Subjective Refraction

For everyday sight testing the head covers sphere from plus 16.75D to minus 19.00D and cylinder to minus 8.00D with auxiliary lens, at a minimum reading of 0.12D where the appropriate lens is fitted. Cross cylinder testing synchronised with the astigmatic axis handles cylinder refinement, and rotary prism supports binocular balance work within the same sitting. Everyday work is handled with no optional fitting required at all.

Hospital, School and Workplace Settings

The manufacturer describes the head as suited to eyesight examination in optical retail, hospital ophthalmology departments, schools and workplace settings. The wide interpupillary span and extended spherical reach are what make that breadth realistic, since screening populations bring a far wider spread of prescriptions and physical dimensions than a settled private practice list.

Fewer Patients Fall Outside the Instrument

Every patient whose prescription exceeds the head's range means improvised trial frame work, a less reliable result and a longer appointment. Reaching plus 26.75D and minus 29.00D with the optional lens, and down to 48mm interpupillary, means far fewer people fall outside what the instrument can present properly. The exceptions are exactly the patients whose refractions are hardest to get right, which is when a proper instrument matters most. Range earns its value at the edges, not in the middle.

Faster Movement Through the Spherical Range

Adjustment across a 3.00D scope in one action of the rotating disc means large changes happen quickly. During subjective refraction the practitioner frequently needs to move well away from the current setting to test a hypothesis, and an instrument that gets there without a long sequence of small steps keeps the examination moving while the patient's attention holds. Attention is a finite resource during subjective testing.

Complete Testing in One Head

Sphere, cylinder, axis, cross cylinder, rotary prism, convergence and near work with the supplied fittings all sit within the same instrument. The patient stays seated and correctly positioned while the examination moves between distance refraction, astigmatic refinement and binocular assessment, and the corneal distance device keeps the geometry consistent across all of it. Fewer transitions also make the appointment easier on the patient.

Optional High Power Lens Set

With the optional plus or minus 10.00D lens fitted, spherical testing reaches plus 26.75D and minus 29.00D. Prescriptions that would otherwise require improvised trial frame work stay within the head.

Standard Spherical Range

In standard form the head covers plus 16.75D to minus 19.00D, which already takes in the large majority of prescriptions met in ordinary practice without any optional fitting.

Fine Minimum Reading

Minimum reading is 0.25D, reducing to 0.12D where the plus 0.12D auxiliary lens or the optional plus or minus 0.12D lens is in use, allowing refinement as far as the patient can discriminate.

Rotating Disc Sphere Selection

Spherical power is located by rotating disc, with adjustment across a 3.00D scope achievable in one action rather than by stepping through every intermediate value in sequence.

Interpupillary Range From 48mm

Adjustment spans 48mm to 80mm in 1mm steps with both sides synchronised. The lower end accommodates children and adults whose interpupillary distance falls below the usual range.

Synchronised Cross Cylinder

Cross cylinder testing at plus or minus 0.25D uses reversal type synchronised with the astigmatic axis, so the axis follows the flip without needing separate adjustment between presentations.

Rotary Prism and Convergence

Rotary prism covers zero to 20 prism dioptres in single steps, and convergence aligns the optical axes at 400mm from the corneal vertexes for near testing.

Near Vision Fittings Supplied

Supplementary fittings are provided for near sight work, so near addition testing does not depend on sourcing accessories separately after the head arrives.

The LINK VT-20 extended range phoropter is specified for the patients who fall outside ordinary limits. Standard spherical coverage runs from plus 16.75D to minus 19.00D, and the optional plus or minus 10.00D lens carries that to plus 26.75D and minus 29.00D. Cylinder reaches minus 8.00D with the minus 2.00D auxiliary lens, minimum reading falls to 0.12D with the appropriate auxiliary fitted, and the astigmatic axis scale covers 0 to 180 degrees in 5 degree steps with cross cylinder testing synchronised to it.

Interpupillary adjustment from 48mm to 80mm accommodates children as readily as adults, rotary prism covers 20 prism dioptres in single steps, and convergence at 400mm from the corneal vertexes supports near testing with the supplementary fittings supplied. The forehead rest travels 16mm, the corneal distance device works against a scale, and effective field of view is 19mm. The head weighs 5kg at 291mm to 323mm wide by 315mm by 85mm, and two colour finishes are described. Which finish and optional lenses a given head includes, along with mounting arrangements, compatible stands, certification status, condition and reseller and listing rights for the manufacturer trademark, all warrant confirming. Contact Medigear.uk, a verified medical equipment supplier, and we will establish the exact configuration on offer.

FAQ

Frequently Asked Questions

Everything buyers need to know about sourcing medical equipment through MediGear.

In standard form the head covers plus 16.75D to minus 19.00D. With the optional plus or minus 10.00D lens in use that extends to plus 26.75D and minus 29.00D. Minimum reading is 0.25D, or 0.12D where the plus 0.12D auxiliary lens or the optional plus or minus 0.12D lens is fitted. Together those spans cover aphakic corrections and very high myopia.

Cylindrical power spans zero to minus 6.00D once an auxiliary lens is in use, and reaches zero to minus 8.00D with the minus 2.00D auxiliary fitted. The astigmatic axis scale runs from 0 to 180 degrees, with each step being 5 degrees. Cross cylinder testing at plus or minus 0.25D is synchronised with that axis scale, so power and orientation are refined together rather than separately.

Adjustment runs from 48mm to 80mm in 1mm steps with both sides synchronised. The lower figure accommodates children and adults with narrow interpupillary distances. If the setting cannot be brought narrow enough, the patient views through the lenses off centre, which introduces unwanted prism and compromises the refraction.

Spherical power is located using a rotating disc, and the arrangement permits adjustment across a 3.00D scope in a single action. Large spherical changes therefore happen quickly, without stepping through every intermediate value, which helps keep the examination moving while the patient stays attentive.

Supplementary fittings are supplied for near sight work, and convergence aligns the optical axes at 400mm from the corneal vertexes with each side moving 2mm inward. Interpupillary distance enabling convergence runs from 57mm to 80mm, so near addition is determined with the eyes converged as they would be in reading. Having the fittings supplied avoids sourcing accessories afterwards.

Rotary prism runs from zero to 20 prism dioptres, a single prism dioptre at a time. That supports phoria measurement, fusional reserve assessment and binocular balance work in the same sitting as the refraction, without repositioning the patient at separate equipment. Single dioptre steps match the resolution at which vergence findings are usually recorded.

The forehead rest adjusts 16mm backward and forward, and the corneal distance device travels 2mm forward and 5mm backward from the standard plane against a scale. Setting corneal distance accurately matters most at the higher powers this head is capable of presenting.

The head weighs 5kg and measures between 291mm and 323mm wide by 315mm by 85mm, the width varying with the interpupillary setting. Two colour finishes are described by the manufacturer, and which one a particular head carries is worth confirming with Medigear.uk.