According to Daily Mail, students at the Massachusetts Institute of Technology created an optical illusion that determines if you need glasses or not. As the image gets larger, who do you see? If you see Albert Einstein, then you have healthy eyes but if you see Marilyn Monroe, you need some specs.
ASAP Science explained the illusion,
“Depending on how well you’re able to focus or pick up contrast, your eye will only pick out details. Up close, we’re generally able to pick up fine details like Einstein’s moustache and wrinkles. But as the distance increases, or if your vision is poor and creates a more blurred image in the first place, your ability to pick up details fades away.”