Are these sneakers mint and grey or pink and white?

Back in 2015, before issues of real substance divided the country, The Dress — seriously, blue and black or gold and white? — was the most hotly debated topic on the internet.

Well, prepare for yet another face-off because people are once again torn, this time over the color of a pair of sneakers.

Facebook user Nicole Coulthard shared a photo of her friend’s Vans to a group known as “Girlsmouth” and asked members if they’re “MINT AND GREY OR PINK AND WHITE???”

MINT AND GREY OR PINK AND WHITE???

Posted by Girlsmouth on Wednesday, October 11, 2017

More than 1,000 users have taken to the post to share their thoughts, with the commenters all posing their many theories.

So how did this debate come about? Coulthard told the Metro that her friend purchased the shoes a few weeks ago and sent a photograph to her mom who replied saying that “blue suited her.” Then, “She texted back saying they are pink, but when she looked at the pic she saw blue too. She sent it to me and I was convinced they are pink, we had a big argument as she said I only said pink because I knew she had bought pink shoes so that’s why I decided to put it up on ‘Girlsmouth.'”

But the bigger question is why people see things so differently.

According to Julia Haller, MD, ophthalmologist-in-chief at Wills Eye Hospital, “Basically, there are two parts of seeing. The first is that light focuses on the retina, and the nerve tissues pick up images; rods help us see in the night, whereas cones help us see in the daytime. There are slight differences at the level of the cones in how we each see color. One way this might be happening is that, in that variability at the level of the combs, by random chance, this image is magnifying that … 0.1 percent individual difference we all have.”

Mystery solved…almost.

Read more from Yahoo Lifestyle:

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• Size 8 beauty pageant contestant considered ‘plus-size’ is all about the ‘in-between’

• Family kicked off Southwest flight for ‘rowdy’ children: ‘We don’t even know what we did wrong’

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