A: Both allow you to log in using facial recognition software.
The increasingly popular tech may seem like a simple and quirky way to unlock your devices and accounts, but it might not be as secure as you think.
In a new paper, researchers show how special glasses can trick commercial-grade facial recognition into thinking the wearer is the account holder.
The software uses deep neural networks to analyse millions of faces and learn how to distinguish between them, relying on features like noses and eyebrows.
As Quartz first reported, the glasses covered these features with a printed pattern to make the computer think it was seeing someone else.
An Asian female wearing the glasses convinced the state-of-the-art algorithm built by the researchers it was seeing a Middle Eastern man.
The glasses cost $0.22 (18p) and worked 87.87% of the time.
The researchers also used the faces of Carson Daly, Colin Powell, Milla Jovovich and John Malkovich.
Researchers printed the glasses on glossy photo paper and simulated a thief entering a building guarded by the tech.
They also tested the commercial facial recognition, Face++, which is used by Alibaba for secure payments and corporate partners Lenovo and Intel.
It was successful 100% of the time.
But in this case, the test was conducted digitally, using glasses edited on to a picture. The researchers said real world success rate may be lower.