MEM Retinoscopy Test (Magnetic) for Welch Allyn

This model is a MEM (Monocular Estimation Method) test plate designed specifically to be used with Welch Allyn retinoscopes.
It is intended for optometrists, ophthalmologists, and eye care professionals who want a reliable, reusable, and easy-to-print MEM tool for clinical use. Designed and tested by an optometrist in a real clinical environment.

The design includes:

• A high-contrast letter layout for accurate MEM assessment
• A precise central window aligned with the retinoscope viewing area
• Magnetic attachment for secure and repeatable positioning
• Rear anchoring feet that clip firmly onto the retinoscope head

🧲 Magnet Placement & Specifications

The model incorporates 6 neodymium magnets, arranged as two groups of three, to ensure a strong and stable attachment.

Magnet specifications:

• Diameter: 8 mm
• Thickness: 1.8 mm
• Alternative: 2.0 mm thick magnets also fit correctly

Magnets are press-fit into the dedicated cavities and should be inserted in the programmed pause. (In the picture there are two BUT THREE ARE NEEDED)

⚠️ Important:
Make sure all magnets are inserted with the same polarity orientation to guarantee correct alignment on the retinoscope.

Printing Notes

• Optimized for PLA / PLA+
• Printed with supports enabled due to the rear anchoring feet
• Supports are intentionally robust to ensure dimensional accuracy, but can be removed cleanly with careful handling
• A planned filament change pause is included:
  • White filament for the base
  • Black filament for letters and high-contrast details

This ensures excellent readability under clinical lighting conditions.

⚙️ Recommended Print Profile

• Layer height: 0.12 mm
• Walls: 3
• Infill: 15–20%
• Supports: Enabled (build plate only)
• Nozzle: 0.4 mm
• Ironing: Disabled (better surface consistency and cleaner text edges)

Clinical Use Disclaimer

This model is intended as a clinical aid and educational tool.
It does not replace certified medical equipment and should be used according to professional judgment.