The world's most famous optical illusion turns 10 years old

The year is 2015. The month is February. A simple story titled 'What colors are this dress?' is published by listicle pedlar Buzzfeed, and the world changes forever. And for the record, I still can't see 'the dress' as anything other than white and gold.

A simple candid photograph of a dress ended up revealing differences in the way people perceive colours, with many unable to see the dress in its original black and blue. Cue millions of debates, tweets and news stories. There's never been a viral fluff piece quite like it since, and with 'the dress' now officially ten years old, it's not only one of the best optical illusions ever, but a reminder of a simpler time online.

"The Dress is a viral meme that launched to stardom on 26th February 2015, when the world disagreed over whether the item of clothing below was black and blue or white and gold," reads a dedicated landing page on the website of Roman Originals, the company that made the dress. "The phenomenon revealed differences in human colour perception which have been the subject of ongoing scientific investigation in neuroscience and vision science, with a number of papers published in peer-reviewed science journals. In popular discourse, the disagreement over the colours was sometimes referred to as "dressgate".

According to the dress's Wikipedia page (yes, it has one), there were various attempts to explain the phenomenon using Science™, but a consensus was never reached. Neuroscientist Bevil Conway suggested it could be related to the ways in which the human brain perceives hues of the sky, telling Wired, "Our visual system is supposed to throw away information about the illuminant and extract information about the actual reflectance ... but I've studied individual differences in colour vision for 30 years, and this is one of the biggest individual differences I've ever seen." And a study in Journal of Vision even suggested "people who were early risers were more likely to think the dress was lit by natural light, perceiving it as white and gold, and that "night owls" saw the dress as blue and black."

While we might never fully understand the differences in perception, we can certainly say that 'the dress' now exists as a reminder of a very different era of the internet. In today's world of infinite content, short-form video and hot takes, the whole thing looks positively twee. For weeks, celebrities and mortals alike debated about the colour of a dress; no hate, no politicising (as far as I recall, anyway), just fun. Remember when the internet used to be fun?

So, let's raise a glass to the dress. While other colour-based optical illusions have come close, none have ever matched it for sheer fun and virality.