Kind of like how when you're camping, you can shield your eyes and still know where the campfire is.

> Because the contact lenses have limited ability to capture fine details (due to their close proximity to the retina, which causes the converted light particles to scatter), the team also developed a wearable glass system using the same nanoparticle technology, which enabled participants to perceive higher-resolution infrared information.

No, putting the contact closer to the retina would improve imaging, because it would have less distance to scatter. Glasses will not fix this. A potential solution would be implanting these nanoparticles directly above the retina, but that's a significantly more invasive option than what's being described here.

https://en.wikipedia.org/wiki/Metamaterial

The article also mentions at the end that the contacts are only sensitive enough to detect IR emitted by an LED - they're not sensitive enough to "see" ambient IR. A far cry from "Contacts let you see in the dark with your eyes closed".