#3 Floaters
All of us have now and then seen weird wormlike shapes floating in front of our eyes. It always gives me a jolt and suddenly I forget everything else for a second. Does it happen to you too? What really are these? Are they just optical illusions that our brain creates or something else?
The answer is here. They are commonly called as floaters.
Read ahead to know what they mean and what they actually are.

#2 Shadows
Yes, they are no optical illusions. They are created tissues, red blood cells or clumps of protein inside the eye. And the reason we see them is because they create a shadow in the retina.
They are known as Muscae volitantes (Latin for "flying flies") or mouches volantes (French). They float slowly in front of our eyes because of the refraction of the light that passes through the retina.
Watch the video on the next page to understand how it works in a simple manner.

#1 The video
Watch this mesmerising video to know what happens.