Visionstar SL-266A1

Optometry and orthoptic teaching clinics are the clearest fit. A set used by a rotating group of students loses small pieces faster than any other, and paired Maddox rods, pinholes, slits, cross-line pieces, plane lenses and cross cylinders keep a teaching session running when one goes missing. Student optometrists in the UK refract under supervision, and a set that covers refraction and binocular vision in one tray suits the full examination sequence they are learning.

Busy community practices see the same pressure in a different form. When several practitioners share one trial case between rooms, a second pinhole or slit in the tray means a lost piece does not delay an appointment. Paired sphere and cylinder powers let both eyes hold identical lenses during binocular balancing.

Hospital eye services and orthoptic clinics draw on the prism ladder, with every whole value from 1 to 10, together with the paired white Maddox rods for heterophoria and torsion measurement. Prism trials in free space show whether a patient will tolerate a prescribed prism before it is glazed.

Screening and outreach programmes use pinhole acuity as a quick indicator of uncorrected refractive error in adults, where population data support it, and the second pinhole lets two eyes or two examiners work without swapping pieces.

Two settings fit less well. Practitioners who rely on ±0.12 D lenses for fine end-points will find the finest step is 0.25 D, and services measuring large deviations will need methods beyond a prism range ending at 10. Institutional and teaching buyers commonly ask for evidence of conformity. The conformity documentation those procurement routes require is issued by the manufacturer and provided by the seller.

Six Accessory Types in Pairs

Plane lenses, white Maddox rods, slits, cross-line pieces, pinholes and cross cylinders each come twice. The second piece serves bilateral testing or stands in when the first goes missing.

Less Downtime From Lost Pieces

Small accessories are among the easiest parts of a trial case to lose. A second one in the tray keeps the test available while a replacement is ordered, which matters most in shared rooms and teaching clinics.

A Prism at Every Whole Value to 10

Prisms run from 1.00 to 10.00 in whole steps, with a pair at 0.50. Moderate deviations can usually be measured with one prism in one cell.

Matched Maddox Rods for Torsion

Two white Maddox rods allow the double Maddox rod test with same-colour rods, the arrangement that avoids the colour artefact reported with mixed red and white rods.

Spheres to 20.00 D in Both Signs

Forty sphere powers in each sign reach 20.00 D, with 0.25 D steps to 6.00 D. The same tray serves routine and high prescriptions.

Cylinders to 6.00 D Without Gaps

Cylinders run in quarter steps to 4.00 D, including 3.25 and 3.75 D, then in half steps to 6.00 D.

Paired Refraction Powers

Every sphere and cylinder power comes as a pair, so both eyes carry identical lenses during balancing.

No Electrical Upkeep

The set has no electrical parts, needs no mains supply and never enters a portable appliance testing schedule.

Convex Spheres

Forty powers, two of each: 0.25 D to 6.00 D in 0.25 D steps; 6.50 D to 10.00 D in 0.50 D steps; 11.00 D to 16.00 D in 1.00 D steps; then 18.00 and 20.00 D.

Concave Spheres

Forty powers, two of each, at the same values as the convex spheres.

Convex Cylinders

Twenty powers, two of each: 0.25 D to 4.00 D in 0.25 D steps, then 4.50, 5.00, 5.50 and 6.00 D.

Concave Cylinders

Twenty powers, two of each, at the same values as the convex cylinders.

Prisms

Twelve prisms: 0.50 in a pair, then 1.00 to 10.00 in whole steps, one of each. No unit is printed.

Plane Lenses

Two plane lenses for occupying an empty cell or checking frame fit.

White Maddox Rods

Two white Maddox rods for heterophoria measurement and double Maddox rod torsion testing.

Stenopaeic Slits

Two slits for locating a principal meridian in irregular or high astigmatism.

Cross-Line Pieces

Two cross-line pieces for centration and alignment tasks in the trial frame.

Pinholes

Two pinholes for pinhole acuity. The aperture diameter is not published.

Cross Cylinders

Two cross cylinders for refining cylinder axis and power. Their powers are not published.

Filters, Black and Frosted Lenses

One red filter, one green filter, one lens listed as black and one frosted lens.

25 mm Reduced Aperture

Every lens has a 25 mm clear aperture. Rim outer diameter is not published.

Single-Side Power Marking

Powers are printed on one side of each handle. Durability under repeated disinfection is not published.

Tray and Case

A tray listed at 530 × 310 × 35 mm in a case of 470 × 370 × 90 mm with a carry handle, weighing 4.8 kg. The photograph shows red and black rims. The case material is not stated.

The SL-266A1 is a set built to keep working: six accessory types in pairs, a prism at every whole value to 10, paired spheres to 20.00 D and cylinders to 6.00 D without gaps, all at a 25 mm aperture. Its finest step is 0.25 D, it states no anti-rotation construction, and its published tray and case dimensions disagree. Medigear.uk lists the SL-266A1 for business buyers worldwide and can arrange delivery, familiarisation and service cover. Request the packing list, confirmed tray and case dimensions, rim outer diameter, pinhole diameter, replacement lens pricing and the declaration of conformity from the seller at quotation.