Visionstar CM-1900C

Low vision assessment is where the larger panel earns its cost. A practice measuring acuities of 6/60 and below works entirely at the top of the chart, where optotypes are largest and where a panel with insufficient area must either crop the target or force a shorter working distance. Patients under monitoring for macular disease, advanced glaucoma and diabetic maculopathy fall into this group, as do those being assessed against certification thresholds, and for all of them a measured value rendered at correct size is the point of the examination.

Long consulting rooms benefit equally. Practices able to work at six or seven metres directly, rather than through a mirror, gain a simpler optical arrangement and a more natural patient experience — but only if the display can render the largest targets at that distance. The 2.0 to 7.0 metre span with accurate optotype scaling makes the full range usable rather than nominal.

Repeat and monitored patients are served by randomised sequencing. Anyone attending frequently sees the same chart repeatedly, and a familiar sequence quietly inflates recorded acuity without any signal the clinician can detect. Randomising each presentation removes the mechanism, which matters most in the pathways where a change in acuity is the outcome being tracked.

Paediatric and communication-limited patients use the alternative chart versions — tumbling E, Landolt C and child optotypes — presented on the same panel at the same distance as the letter charts, so results across patient groups remain comparable. Two commissioning points deserve attention: the working distance must be measured and set accurately, since optotype scaling depends entirely on it, and the panel must be sited clear of direct sunlight and strong reflected light, which degrade a monitor chart more readily than insufficient brightness does.

Room for the whole acuity range

Twenty-three inches renders the largest optotypes at correct size across the full 2.0 to 7.0 metre span. A smaller panel forces a choice between cropping the target and shortening the working distance, and neither is a good answer.

Built for the top of the chart

Low vision assessment happens where targets are largest. A practice measuring 6/60 and below is working at exactly the point where panel area becomes the limiting factor, and this is where the extra inches pay.

Lower power than a smaller panel

At 33 W the display draws less than a smaller LCD chart monitor and roughly a third of a halogen projector with its overheads. In a small closed consulting room that shows up as heat rather than as a bill.

A chart that cannot be memorised

Randomised sequencing removes the most common cause of falsely good acuity in repeat attenders. There is no way to detect a recalled line from the responses, so eliminating the possibility is the only reliable answer.

Works in a lit room

Producing its own light at 250 cd/m², the panel holds contrast regardless of ambient lighting. The examination does not depend on how well the room can be darkened, which suits shared and multi-purpose spaces.

The room sets the distance, not the chart

Precise scaling across 2.0 to 7.0 metres means acuity is correct for the room as built. Premises that fall short of a nominal six metres, or exceed it, are both accommodated without compromise.

Every patient group on one panel

Tumbling E, Landolt C, letters, numbers and child charts all present at the same distance on the same display, so results from preschool children, non-Latin readers and letter-naming adults remain directly comparable.

Axis by rotation, not interpolation

The rotating astigmatic fan converges on the cylinder axis directly rather than requiring the clinician to interpolate between fixed meridians — faster, and less prone to rounding error.

Nothing to replace or align

No lamp, no fuse, no screen to clean separately and no projection geometry to check. A wall bracket, a level and a measured distance are the whole installation.

23-inch flat screen LCD display

A 23-inch colour LCD panel renders all charts at high resolution with enough area to display the largest optotypes at correct size across the full distance range.

Acuity range 6/3 to 6/150

Chart acuity spans 6/3 to 6/150, equivalently 20/10 to 20/500 or 0.04 to 2.0 decimal, with headroom above normal vision and reach well into low vision.

Randomised test sequencing

Optotype order is randomised at each presentation, preventing repeat patients from recalling the sequence rather than resolving it.

Multiple chart versions

Tumbling E, Landolt C, letters, numbers, child optotypes and special version charts cover patients who can name letters and those who cannot.

Rotating astigmatic fan chart

A rotating fan target allows cylinder axis to be found by rotation, described by the manufacturer as a fast and accurate route to cylinder and axis.

Precise distance adjustment 2.0–7.0 m

Optotype size scales to the working distance set anywhere between 2.0 and 7.0 metres, so acuity is correct for the room as built rather than a nominal figure.

250 cd/m² brightness

Panel luminance of 250 cd/m² sits within the range conventionally recommended for acuity charts and holds regardless of ambient room lighting.

33 W power consumption

Total consumption stays at or below 33 W, lower than smaller LCD chart displays and markedly lower than a halogen projector, with correspondingly less heat.

AC 100–240V universal supply

The power input accepts 100–240V at 50/60 Hz, covering UK mains at 230V nominal without adaptation or a regional variant.

Wireless IR remote control

An infrared remote drives chart selection and sequencing from the clinician's working position, running on standard batteries.

530 × 390 × 120 mm at 5.5 kg

The unit measures 530 mm wide, 390 mm high and 120 mm deep at 5.5 kg, shallow and light enough for a straightforward wall fixing or desk stand.

Easy wall or desk mounting

Installation requires only that the panel be level and square to the patient, with no throw distance to calculate, no screen to position opposite and no projection alignment.

Smooth and quiet operation

Chart changes are silent, with no mechanical mask plate or chart wheel, which suits patients who find equipment noise distracting.

High-contrast panel

The manufacturer specifies a high-contrast display, supporting clean optotype edges at the acuity limits where the measurement is actually decided.

The Visionstar CM-1900C is a 23-inch flat screen chart monitor whose panel size does real clinical work. Acuity charts are largest at the top, and those targets scale up with working distance — so a display with enough area is what allows the full 6/3 to 6/150 range to be rendered at correct size all the way out to seven metres, rather than cropped or compensated for with a shorter room. That matters most in low vision assessment, where the top of the chart is exactly where the patient is being measured. Randomised sequencing prevents repeat attenders memorising the order, tumbling E, Landolt C and child optotypes cover patients who cannot name letters, and a rotating astigmatic fan finds cylinder axis by rotation rather than interpolation. At 33 W it draws less power than smaller panels and a fraction of a halogen projector, on a universal 100–240V supply with no lamp, screen or alignment to maintain. Set the working distance accurately at commissioning and site the panel clear of direct and reflected light. Medigear.uk supplies the CM-1900C into the UK with pre-despatch functional inspection, documentation review and mounting guidance. Contact the Medigear.uk team for current pricing, quantity quotations, bracket options, or bespoke configuration enquiries.