Are your eyes playing tricks on you? You may want to sit for this.
Twitter account Unusual Facts was certified as viral – with more than 70,000 reactions – after posting side-by-side photos demonstrating what a "normal" eye sees compared to a person with astigmatism.
A traffic shot features car lights that appear to be burned and stretched in a blur – while in the other the car lights seem more in focus and localized.
The seemingly simple visual advisor to Unusual Facts is freaking out thousands of people who thought they were seeing things like everyone else for life.
"Listen, I'm in the school bathroom now, I did not ask for an existential crisis while I'm taking a t" @SamtheToaster tweets.
"I had no idea that this was a thing! Honestly, I thought the light worked !!! add @VesuvianVoice.
"… My life and see is a lie, I thought everyone saw the lines" posts AmbientGryph.
"EVERYTHING MAKES SENSE NOW, I THOUGHT THAT I JUSTIFIED WITH PERCEPTION OF DEPTH. I HATE THAT," shouts @SyrisReigns.
"I was years old when I discovered that I have astigmatism" cracks @PureBredGay, exhibiting a more humorous outlook than many of the seemingly shocked commentators on the topic.
"Astigmatism is when the cornea is slightly curved and not quite round" the post says. "With astigmatism, the light focuses on several points of the retina instead of just one point. This is what people with astigmatism [see] vs. [those] without."
A curve in the cornea causes this blurred vision, as it prevents light from concentrating properly in the retina – but the exact cause of astigmatism is unknown, according to the American Optometric Association (AOA).
The condition is present from birth for most people and may improve or worsen with age, according to the AOA report.