A diagnostic medical tool is described that allows patients to non-invasively observe, describe and document their own retinal blood vessels using the Purkinje vascular entoptic test.We envision key applications of the Purkinje retinal image stabilization (PRIS) device in monitoring of diabetic retinopathy and cost-effective assessment of retinal visual acuity.To optimize Military Airplane our PRIS principle, we have developed a benchtop device with Crop Tee interchangeable light modules.The modular design is intended to provide maximum flexibility for determining appropriate PRIS stimulation parameters.In self-tests, we found that a pleasant entoptic perception occurs when a green luminous light spot (approx.
525 nm) moves on a circular path.The challenging part is to derive an objective diagnosis from a subjective phenomenon.