A 'living' prosthetic iris.

AIM

To design and demonstrate dynamic pupils, which react to light for use with ocular prostheses.

METHODS

The realism of ocular prostheses is limited by the immobility of the pupil. Our solution is to use a liquid crystal display (LCD) in the prosthesis to vary the pupil size as a function of the ambient light. Several liquid crystal cells were fabricated and tested for survivability through the ocular prosthesis manufacturing process. The dynamic pupil is controlled by a novel and entirely autonomous, self-powered passive electronic circuit using a solar cell, matching the minimum diameter of the pupil.

RESULTS

The first LCD surviving the rugged conditions of the ocular prosthesis manufacturing steps and an entirely passive circuit controlling the pupil have been demonstrated for the first time to our knowledge. A design for a complete prosthesis with a dynamic pupil has been proposed. Finally, a standard device for the mass production of ocular prostheses is presented.

CONCLUSION

We have shown that a practical solution for an autonomous self-powered dynamic pupil is possible, given the constraints of size, fabrication process, weight, cost and manufacturability on a mass scale. We envision that the LCD could be mass produced, and only the final steps for the integration of the iris matched to a patient would be necessary before assembly using standard processing steps for the production of the prosthesis. Using a clinical trial, we hope to demonstrate that the dynamic pupil will have a positive impact on the quality of life of patients.