[rexignis]

Unless I missed something when we were covering eye physiology at uni, contact lens screens are useless. The area we can actually attend to and process data is tiny, which means the screen has to be directly in the center of the contact.

For example: A physically separate screen means you can swivel your eyeball and look at a different bit of text on a book page, or a different character on a movie screen. With a contact lens display the content you are attending to is always on the center and swiveling your eyeball to change targets will do nothing.

[sillysaurus3]

If the lens knows its own orientation, then its display can change with the orientation. The lenses themselves don't need to embed gyros. I can imagine wearing an upside-down U over the bridge of your nose which has embedded sensors that measure where you're looking.

[wyager]

>swiveling your eyeball to change targets will do nothing.

Unless you put a MEMS accelerometer/gyro on the contact lens and change content as the user moves their eye.

These are engineering problems, not insurmountable physics problems. Saying stuff like "contact lens screens are useless." is unrealistically pessimistic :)

[cma]

Pair it with eye tracking. Main problem I see with it is LEDs on a contact lens wouldn't be in focus, at least without some other optics to make them more directional.

[mistercow]

That problem seems reasonably solvable.

The main problem I see is that saccades are ridiculously fast, so not only does the eye tracking have to be extremely precise, but the latency for the track-update-display pipeline has to be tiny.

This problem is already difficult for head motion. Doing it at the eyeball level is way more ambitious.

[probablybroken]

I'd imagine applications even with a low res, blurry display might include directional indicators and notification lights in the periphery of the users vision. This would only require a ring of a few LEDs round the edge of the device and would be more discreet than e.g. glass.

[whtrbt]

Is it feasible to move the content instead?