Modular Human Eye – 4-Colour Anatomy & Cataract Model

A modular, four-colour right-eye teaching model designed for explaining gross eye anatomy and the concept of cataract.

The globe is approximately 117 mm in diameter, representing a nominal 5× enlargement. Six main printed pieces make the model easy to open and reassemble, without magnets, screws or separate pins.

FEATURES

• Unified lower body: the lower scleral, choroidal and retinal sections form one physical assembly.
• Removable upper half with a broad stepped dissection: a large scleral section is removed to expose the choroid, followed by a deeper cut exposing the retina.
• Raised, branching choroidal vessels and separate retinal vascular arcades on the inner retinal surface.
• Shortened medial and superior rectus muscle sections with white tendon ends and longitudinal fibre detail.
• Removable cornea, iris and biconvex lens.
• Two integral locating pins on the lens mount to reduce rocking.
• Tapered sliding pins, flared socket entrances and a keyed display base.

FOUR-COLOUR LAYOUT

White: sclera, cornea, lens, tendons and mechanical details.
Brown: choroid, ciliary tissue and iris.
Yellow: retina.
Red: vessels and muscle sections.

The colours are instructional. The normal cornea and lens are transparent; the opaque printed lens illustrates the concept of cataract rather than a specific cataract morphology. The cornea can optionally be printed separately in translucent filament.

PRINTING

Suggested starting settings:
• 0.4 mm nozzle.
• 0.16 mm layers; optionally 0.12 mm for the detailed upper half.
• 3–4 walls.
• 5 top/bottom layers.
• 10–15% infill in bulk regions.
• Supports as required beneath curved surfaces, overhangs and sideways pins.
• Print at 100% scale.

Use the colour 3MFs for multicolour printing. Import each as one assembly and preserve the relative positions of its material bodies. The STL files provide single-material equivalents.

The files were prepared around a FlashForge Creator 5 workflow, but contain generic geometry rather than printer-specific settings or G-code.

FIT AND ASSEMBLY

Print the included fit samples first using the same material and compensation settings as the model. They provide 0.15, 0.25 and 0.35 mm diametral clearance options; the model uses 0.25 mm.

Place the lower body on the keyed base, then insert the lens, iris and cornea. Lower the upper half evenly onto its three locating pins.

To open, lift the upper half straight up. Remove the cornea forwards, then lift out the iris and lens.

These are sliding locating joints, not locking latches. Support the lower body when handling the assembled eye.

ANATOMICAL SCOPE AND VERSION STATUS

This is a reference-informed gross-anatomy demonstrator. Tissue thicknesses, vessel relief and muscle detail are simplified or strengthened for printing. The muscle sections do not reproduce complete orbital courses, and microscopic retinal and choroidal layers are not individually represented.

V4 has passed digital mesh, assembly-interference and sampled removal-path checks. Physical fit and durability testing remain pending.

The complete download includes STL and colour 3MF files, fit samples, assembly instructions, anatomical references, editable Python source and mesh-rendered previews.

Creative Commons Attribution–NonCommercial–ShareAlike 4.0 (CC BY-NC-SA 4.0).

It allows others to:

• Modify and share your model.

• Use it noncommercially, without selling the files or prints.

• Share modifications under the same licence, keeping them noncommercial.

• They must credit you.