In reality, I have a hard time imagining that anyone would be able to distinguish anything meaningful from a display on a contact lens. That's like suggesting that you could read a printed word on a contact lens today. You wouldn't be able to focus on something that is directly on your eyeball.
I think in addition to the technical challenge of actually getting something like this working in a contact lens, the issue of physically being able to make use of such a device needs to be addressed.
To those suggesting a pair of glasses be used instead, I think this is a more practical suggestion for both reasons (the biological and technical). If I try really hard I'm barely able to focus on something as close as my glasses.
FTA: "By now you’re probably wondering how a person wearing one of our contact lenses would be able to focus on an image generated on the surface of the eye. After all, a normal and healthy eye cannot focus on objects that are fewer than 10 centimeters from the corneal surface. The LEDs by themselves merely produce a fuzzy splotch of color in the wearer’s field of vision. Somehow the image must be pushed away from the cornea. One way to do that is to employ an array of even smaller lenses placed on the surface of the contact lens. Arrays of such microlenses..."
I get the sense they underestimate how hard it will be to get the optics right for that in a contact lens. It might be worthwhile to forget all the electronics to begin with and just focus (no pun intended) on making a static figure viewable via microlenses and then build from there.
Another issue is that contact lenses need to breath. They admit in the article that gas permeability is affected as features are added to the lens, so I'd think glasses would be a safer option.
I think in addition to the technical challenge of actually getting something like this working in a contact lens, the issue of physically being able to make use of such a device needs to be addressed.
To those suggesting a pair of glasses be used instead, I think this is a more practical suggestion for both reasons (the biological and technical). If I try really hard I'm barely able to focus on something as close as my glasses.