Optical illusion with woman's hidden face can only be seen by

We love a good optical illusion and this one is up there, but it may make you feel a tad dizzy if you look for too long.

Optical illusion hides images only 'two per cent of' people can

Optical Illusion for Testing Your IQ: Only 1% can spot 4 faces

Everyone can see the woman in the hat - but you could have 20/20 vision if you can spot the hidden face in the illusion

Optical Illusion: Can You Spot the Hidden Woman's Face in This Art? - Times of India, Optical Illusion

You have 20/20 vision if you can spot the third face in eerie

Three visual illusions that reveal the hidden workings of the brain - The University of Sydney

Ambiguous image - Wikipedia

What Is An Optical Illusion?, Blog

50 Optical Illusions That Will Blow Your Mind - Parade