Light in visible spectrum is emitted by the contact lenses. There can be no optical focusing for that light. No image formation on the retina. That means the user may see that there is IR light somewhere around, possibly the general direction where it's coming from (left vs right), but that's all. No IR image, not even general shapes.
Several recent posts, think this one has the most discussion:<p><a href="https://news.ycombinator.com/item?id=44063051">https://news.ycombinator.com/item?id=44063051</a>
Very cool but:<p>> Currently, the contact lenses are only able to detect infrared radiation projected from an LED light source, but the researchers are working to increase the nanoparticles’ sensitivity so that they can detect lower levels of infrared light.<p>> “There are many potential applications right away for this material. For example, flickering infrared light could be used to transmit information in security, rescue, encryption or anti-counterfeiting settings.”<p>Hmm
<i>> In humans, the infrared contact lenses enabled participants to accurately detect flashing morse code-like signals and to perceive the direction of incoming infrared light. “It’s totally clear cut: without the contact lenses, the subject cannot see anything, but when they put them on, they can clearly see the flickering of the infrared light,” said Xue.</i><p>Sounds like promising tech but that’s not "seeing in the dark", yet.
You do not "see" in the dark with these lenses in any meaningful way. They just light up in the visible spectrum when infrared light is shone on them.