Scientists at the University of Washington are working on a human machine interface where LEDs are embedded into contact lenses in order to display information to the wearer. This human machine interface will use custom-built transparent circuitry in a polymer lens that is roughly 1.2 millimeters in diameter.

Babak Amir Parviz, the leader of the research group, said, "We're starting with a simple product, a contact lens with a single light source, and we aim to work up to more sophisticated lenses that can superimpose computer-generated high-resolution color graphics on a user's real field of vision." Parviz added that single pixel visual cues for gamers and the hearing impaired are already quite possible with the lens prototypes. The group has also experimented with non-invasive biomonitoring including checking glucose levels for diabetics.

There are some obvious challenges of realizing this concept - as regular circuitry and LEDs are incompatible with regular contact lenses, every piece of this project must be fabricated from scratch. And the group must attempt to fit transistors, radio chips, antennas, diffusion resistors, LEDs and photodetectors onto a miniscule polymer disc. Additionally, the team is required to control lens position and light intensity relative to the pupil. Finally, because the lens is so close to the corneal surface, images must be projected away from the cornea using either micro-lenses or lasers. To ensure the safety of users, the lens should protect the eye against chemicals, heat and toxins, and the components must be semi-transparent in order for the wearer to view their surroundings.

Read Parviz's complete seven page article, Augmented Reality in a Contact Lens.