Red dot illusion tests eyesight

The latest optical illusion puzzling people across the internet is a simple red dot.

While some illusions test your brain, this one tests your eyesight. If you look closely and hard enough, you should be able to see an image inside the red dot.

Do you see it?

How about now?

What do you see?

Keep looking. Calm your mind and stare at the circle.

Get a good look here and find the hidden image.

Some people saw the image pretty quickly. Others saw an outline. Some couldn't see anything in the dot.

The hidden image is...

It's a horse with a saddle standing in the grass.