This optical illusion will make you question what you're seeing

Appearances can be deceptive, and the Internet knows this very well. Optical illusions are regularly shared, or resurface after many years. And these very varied images never fail to amaze us. It seems that each one manages to manipulate a loophole in our brains to make us see (or not see, precisely) a detail. This particular optical illusion will turn your brain upside down.

Really parallel lines

So what do we see in this optical illusion? It looks like a city from above, with greyish squares separated by green lines. But when you focus on a point in the image, the lines at the ends of this centre do not appear to be straight! The image is a 3D one without any animation or special effects.

A confusing sight

After some research, it was found that this illustration was designed by Lesha Porche. This image is tailored to challenge your visual perception. According to Prof. Michael Bach, it has to do with the way our eyes interpret signals. He explains on his website that:

The tiles contain a low-resolution brightness curve, which is obscured by all the borders. (...). The blurring occurs automatically in our visual system, because - largely unnoticed - our visual resolution drops rapidly from the centre of the gaze: at 10° eccentricity, our visual acuity is 1/10th that of the centre.

Yet the periphery doesn't look blurry, does it? Its sharpness is 'invented' by our visual system, just as our blind spots are 'filled in'.

This article was translated from Gentside FR.

Sources used:

Prof. Michael Bach: 'Peripheral Curved Line Illusion'