Interactive Gaze Simulator

A free 3D teaching model of how the eyes move, created by Dr Robert Burke, optometrist at Calgary Vision Centre. Move the target and watch both eyes follow, then apply a sixth, fourth or third nerve palsy, internuclear ophthalmoplegia, thyroid eye disease or another eye-movement disorder and see how the eyes behave in each direction of gaze.

There are two modes. The Simulator lets you explore a condition. The Motility chart works the other way round: record where each eye pointed in the nine positions of gaze and it suggests which conditions best fit.

Who it is for

Optometry, ophthalmology and neurology students learning the extraocular muscles and cranial nerves, and clinicians explaining double vision to patients.

How to use it

• Move your pointer over the face, drag with a finger, or use the 3×3 pad to look in the nine diagnostic positions.

• Pick a condition and the affected side. Each one has a short teaching card with the signs and the red flags.

• Click the face to lock the gaze; press and hold the face to compare with a healthy patient.

• Switch the fixing eye to see the larger secondary deviation, or switch to a near target to see convergence.

• Every case has its own link, so you can share exactly what you are looking at.

Conditions

• Sixth nerve palsy: the eye cannot turn out.

• Fourth nerve palsy: the eye rides high, worst looking down and in.

• Third nerve palsy: ptosis, a dilated pupil and an eye that rests down and out.

• Internuclear ophthalmoplegia: one eye fails to adduct on side gaze.

• Thyroid eye disease: tight muscles limit elevation and abduction.

• Also in the simulator: orbital floor fracture, Brown syndrome, Duane syndrome, cavernous sinus syndrome, myasthenia gravis, Miller Fisher syndrome and skew deviation.

About the model

This is a qualitative teaching model, not a biomechanical simulation. It keeps eye movements within normal ranges, separates weak muscles from tight ones, and applies Hering's law through the fixing eye. It does not model pupil light reactions, torsion or head tilt.

Educational use only. This simulator does not examine anyone's eyes and is not a diagnostic tool. New double vision, a drooping eyelid, a change in pupil size, or eye-movement problems with headache, weakness or dizziness need urgent medical assessment.