There are many optical illusions, both natural and man-made, that can trick your brain… every time. The visual illusions are characterized by visually perceived images that differ from objective reality. The information your eyes gather doesn’t match the source in some way, causing a major (awesome) headache.
There are three main types of illusions: “literal optical illusions that create images that are different from the objects that make them, physiological ones that are the effects on the eyes and brain of excessive stimulation of a specific type (brightness, colour, size, position, tilt, movement), and cognitive illusions, the result of unconscious inferences.”
This photo series by Rose-Lynn Fisher captures tears of grief, joy, laughter and irritation under the microscope.
The tears from your eyes aren’t just water. They’re primarily made up of water, salts, antibodies and lysozymes, but the composition depends on the type of tear. There are three main types – basal tears, reflex tears, and weeping tears.
As you can see, they can look incredibly different when evaporated and placed under a microscope.
More info: http://bit.ly/RJqvK7
Images by Rose-Lynn Fisher, via the Smithsonian Magazine and ScienceAlert.
tears : when you are sad and you cry, tears come out of your eyes.
grief : strong sadness