Optical Illusions

By: Bailey Ulmer

What is an optical illustion?

An experience of seeming to see something that does not exist or that is other than it appears.


What is the retina?

The retina is the innermost coat of the posterior part of the eyeball the receives the image produced by the lens, is continuous with with optic nerve, and consist of many different layers.

What is the Iris?

The Iris is a contractile, circular diaphragm forming the colored portion of the eye and containing a circular opening, the pupil, in its center.

What is the lens?

The lens is a piece of transparent substance, usually glass, having two opposite surfaces either both curved or one curved and one plain, used in an optical device in changing the convergence of light rays, as for magnification, or in correcting defects of vision.

What is the cornea?

The cornea is the transparent anterior part of the external coat of the eye covering the iris and the pupil and continuous with the sclera.

What is the optic nerve?

The optic nerve is one of the second pair of cranial nerves, consisting of sensory fibers that conduct impulses from the retina to the brain.

What are the rods and cones?

The rod sensitivity is shifted toward shorter wavelengths compared to daylight vision, accounting for the growing apparent brightness of green leaves in twilight.

The cones are less sensitive to light than the rods, as shown a typical day-night comparison. The daylight vision (cone vision) adapts much more rapidly to changing light levels, adjusting to a change like coming indoors out of sunlight in a few seconds.

Optical Illusions

Look at the black cross for 20 seconds. Do the pink dots disappear?

Do you see a face or a women walking by a tree with the city in the background.

Old women with a guy as her face. A man with a ukulele player as his face.

A skull and a women.

You should see a normal person on the right.

A young girl and an old man.

The dots aren't moving in a circle. They all move in their own line.

You should see a dot going in a circle.

References

Dictionary.com

Google Images: Optical Illusions