Smart Contact Lenses Tell You Where To Go

Image from the paper with items a-d. a) Schematic of the EC navigation system integrated with a smart contact lens consisting of GPS receiver module, Arduino UNO as a processor, and PB display. b) Photograph of contact lens placed on the 3D printed replica eyeball. c) Camera setup of the navigation system on the dashboard of a car. d) Driving schemes updating the direction signal: (1–4) images show the four cases of operational principles used in the navigation system. Based on 0.2 V applied to the common pin, 0 V (off-state) and 0.7 V (on-state) are applied alternately in 5 WEs, and operating voltages with relative voltages of −0.2 V and 0.5 V are obtained (From the figure reads left to right: the name of 6 pins used in the system, their on–off status, the applied voltage, and relative voltage). Scale bar is 2 mm.

Augmented Reality (AR) promises to relieve us from from the boredom of mundane reality and can also help you navigate unfamiliar environments. Current AR tech leaves something to be desired, but researchers at the Korea Electrotechnology Research Institute have brought AR contact lenses closer to actual reality.

The researchers micro-printed FeFe(CN)6 ink onto the contact substrate and thermally reduced it at 120˚C for nine seconds to form Prussian Blue, an electrochromic pigment. By confining the material with the meniscus of the ink, resolution was better than previous techniques to display data on contact lenses. While the ability to reversibly change from clear to blue faded after 200 cycles, the researchers were targeting a disposable type of smart contact lens, so degradation of the display wasn’t considered a deal breaker.

Since voltages applied were constant, it seems this isn’t a true bi-stable display like e-ink where power is only required to change states. The on condition of a section required 0.5 V while off was -0.2 V. The researchers printed a contact with straight, left, and right arrows as well as STOP and GO commands. Connected to a GPS-equipped Arduino Uno, they used it to navigate between ten different checkpoints as a demonstration. Only a 3D printed eyeball was brave enough (or had IRB approval) to wear the contact lens, so watching the state change through a macro lens attached to a smartphone camera had to do.

With more AR devices on the way, maybe it’s time to start embedding household objects with invisible QR codes or cleaning your workshop to get ready for your AR workbench.

26 thoughts on “Smart Contact Lenses Tell You Where To Go

  1. Cyanide in the eyeball. Hmm.
    Interesting that cyanide in Prussian Blue is not toxic, for the same reason it is so toxic when the CN is free to roam around: it binds so tightly to the iron atom that even oxygen can’t shake it loose. What makes Prussian Blue dye is what makes hemoglobin die. (ok, the hemoglobin survives, but outlives its host).

    1. This is the sort of thinking that started the anti-vax movement.

      Elemental chlorine is quite deadly and elemental sodium violently reacts with water. Yet you couldn’t live without salt.

  2. And it’s funny when an academic paper has to struggle to find a marketable application for its technology, even when it’s plainly obvious the application as described simply cannot work: There is no way you can focus on a dyed ‘print’ inside a contact lens.

    I also find it pretty difficult to believe you can hide a GPS receiver in the contact lens too, but it’s easy enough to carry a wristwatch with a receiver in it to drive the eyeball display.

  3. Could anyone explain, how an eye is supposed to focus on an image placed on its surface as well as on objects more or less at infinity? This seems achievable only with holographic displays.

  4. Solution in search of a problem.

    Contact lenses are made to correct vision or change your eye color. They were originally invented for aesthetic reasons. If you don’t have eye problems and aren’t an actor or a diver, then you don’t have any reason to use contact lenses aside from personal preference. They’re irritating to the eyes, difficult to maintain, can’t be worn by everyone, and can cause serious infections and other complications from sustained use if you’re not careful.

    Glasses are the only option that works for everyone. Nearly everyone can put on a pair of glasses, and many are forced to wear them often for protection when on the job or outside in the sun. You are not going to convince the general population to suddenly become comfortable with touching their exposed eyeballs to insert contact lenses if they don’t have an occupational reason or an eye problem to begin with, and you are not going to impress anyone that already has issues with wearing them.

    What a waste of effort to even spend the time researching this as a potential application. Try asking actual users of contact lenses before you start trying to smart-ify them.

    1. I have worn glasses almost my whole life and past six years I wear contact lenses. If I didn’t have to, I wouldn’t use any optical aid. Lenses are a PITA, but pros outweigh cons so I use them.

  5. “They’re irritating to the eyes, difficult to maintain, can’t be worn by everyone, and can cause serious infections and other complications from sustained use if you’re not careful.”

    My personal experience, YMMV:

    I have been wearing contacts for over 35 years. Number of eye infections in that period: zero.
    My cleaning discipline is absolutely horrible: I clean them when my vision starts to blur, which is at most once a month. Irritating? Most of the time I don’t notice they are there.
    Disclaimer: I use the rigid oxygen permeable lenses. The soft lenses require very strict cleaning discipline, as they easily acquire protein buildup.

  6. AFAIK the eye can’t focus on such a near object as a contact lens. Unless there is a dedicated zone with proper “lens” correcting the focus of the display elements. For AR this focus needs to change when the display zones are on and off.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.