Optometry Tumbling E – Visual Acuity Optotype

Tumbling E optotype used for visual acuity testing, especially in pediatric or non-verbal patients. Also known as Snellen’s E or Directional E. This model follows standard optotype proportions: Overall design based on a 5 × 5 grid Each stroke and gap = 1/5 of total height Maintains proper geometry for clinical-style testing Default dimensions: 127 mm × 127 mm × 10 mm (5" × 5" × 10 mm) You can scale the model in your slicer (e.g., Bambu Studio) depending on your desired testing distance and visual acuity level. Important Note: Actual visual acuity level depends on viewing distance. This model preserves correct proportions, but to match specific acuity levels (e.g., 20/40, 20/20), appropriate scaling and testing distance must be applied. Printing Tips: No supports needed Works great in PLA or PETG Use 0.2 mm layer height for clean edges Recommend 3–4 walls for durability (clinic use) Use Cases: Pediatric visual acuity testing Vision screening tools Teaching/demo model for optometry stude