FANTASTIC
Optical Illusions!!!
Young Girl – Old Woman
If you look closely you will see either a young girl or
an old woman. If you don’t look for the image that
you originally saw, you will see the other one.
Everyone can’t see both. Can You?
Impossible Triangle
Look at how this triangle was
built. If you know a
mathematician, architect or
have a math teacher who has
net access, tell him/her to
check this out. Logically it just
Necker Cube
Keep your eyes on the dot.
Is it in front, or in back of
the cube? In front or in
back - That is the question!
Rabbit or Duck
This illusion is similar to the young
girl - old woman illusion. Here is a
helpful hint: the Rabbit faces one
direction, and the duck the other
Möller-Franz Illusion
Are these two
lines the same
size?
The arrowheads
are what causes
the confusion. If
you use a ruler
you will see that
the lines are the
exact same size.
Lets see you make this?
Impossible Trident
If you look
closely at
the crate,
you will
see that it
can not be
built, only
drawn.
Impossible Crate
Spirit Catcher
Make sure you are relaxed.
Keep your eyes on the
lighter areas where the
black lines intersect. You
should probably notice
circles coming from the
center of the design. The
trick is that a light color
appears brighter when it
contrasts against a darker
color. So, people see the
areas adjacent to the
intersections to be slightly
brighter, causing what
The Bird
This is a great trick. It works everywhere. When
you read the the above box, did you say the - the
or did you see the "double the". If you you did, did
you catch it in this little blurb???
Schröder Stairs
In this
illustration, the
stairs should
turn upside
down during a
steady gaze. The
wall with the
floating glass
sphere will shift
from the
foreground to
the background.
Of course, if you
originally saw
the background
as the
foreground, you
will notice a
change from the
background to
Stare at the picture (on the left) for about 45
seconds. Then, stare at the white section of this
image (the right section). You should see the Queen
again. Keep your concentration, and for those 45
seconds, don't take your eyes off the picture.
Queen Elizabeth II
Do you think that
these lines are
parallel? They
are! But it
doesn't look like
it does it? We
suppose that's
what makes it an
illusion!!!
The Zöllner Illusion
Blind Spot
Blind Spot and the "Filling-in" phenomenon.
Did you know that your eyes have blind spots (and not just at the back of
your head)? Each of your eyes contains an area that has no
photoreceptors because it is occupied by the optic nerve. You may not
have noticed these areas because they are on opposite sides of your
visual field. However, this exercise is designed to isolate your blind spot
and you will be amazed at the results.
Instructions: Close your left eye and fixate your right eye on the cross
in the first diagram. If your eye is about 12 inches (30 cm) away from the
monitor, you should notice that the round dot disappears. This distance
may vary according to the screen resolution you have set.
Twinkle, twinkle - The Blinking Effect
Challenge yourself to try and count the
dots in the diagram below. Despite a
static image, your eyes will make it
dynamic attempting to "fill-in" the white
circle intersections with the black of the
background. Quite an amazing effect!
Instructions: Simply stare at the white
circles and notice the intermittent
blinking effect.
Borders and Framing Color
Colors often appear brighter and more vibrant when they
are bordered by frames. Black lines are commonly used to
enhance colors in applications like stained glass. This
tactic creates a certain effect, as shown below, and
prevents color clashing. Notice that the drawing on the left
colors appear significantly brighter and pure.
Chromatic Adaptation
Have you ever entered a movie theater on a sunny
afternoon? The room probably appeared completely dark but
as your visual system adjusted to the reduced level of light
you were able to see better after a few moments.
This "adaptation mechanism" allows our eyes to recover from
an oversensitivity to a particular stimuli. "Chromatic
adaptation" occurs when our eyes adjust to certain color
stimuli. Follow the instructions below and see how the visual
system responds to a color overload.
Instructions: Fixate upon the black spot in between the
uniform cyan and yellow areas for about 30 seconds. Then
scroll down and shift your gaze to the black spot in the 2nd
image. Note that the image of the seaplane appears
approximately uniform after this adaptation.
Chromatic Adaptation
Chromatic adaptation allows us to interpret
color within the context of their surroundings.
Altering these surroundings, however, can
sometimes be an "eye-opener".
Instructions: Below is a outdoor picture that
has been covered with a cyan filter. Looking
at the person who is not raising her hands,
what color would you say her brightly colored
top is?
Color Blindness
Almost 10% of human males experience color vision
deficiency (compared with 0.4% of females). The most
common form of these abnormalities is characterized by an
inability to distinguish between red and green hues.
Instructions: The following images are part of The Series
of Plates Designed as a Test for Colour-Deficiency by
Shinobu Ishihara M.D. which is the accepted standardized
color blindness test. They are specially adjusted to isolate
the exact deficiency experienced by the viewer. What do
you see in the plates?
This is a test plate in which
everyone should see a "12".
This plate is designed to separate the type of color
defectives and the level to which they are observed. Most
will see the number "26" clearly while some will only see a
"2" or a "6" or no numerals at all.
Can you trace a line from one "X" to the other? Someone
with normal color vision will trace a orange/brown purple
line and those with a slight deficiency will follow a different
path.
Recognition of Patterns
Although there are no actual triangles that appear on your
eyes' retinas, your brain will somehow interpret the following
image as two overlapping triangles. Is this imagination? Are
you losing your mind? No, the notched circles and angled
lines merely suggest gaps in which objects should be. The
brain does the rest by triggering a sort of pattern recognition
phenomenon.
Opponent After-images
The nature of our visual system
allows us to sometimes see "afterimages" which appear once the
original stimuli are removed. In the
following demonstration, you will see
that the colors in after-images are
usually the opposite
(complementary) colors of the
original.
Instructions: Stare at the black spot
in the center of the four colored
squares for about 30 seconds. Then
scroll down and move your gaze to
the black spot in the uniform white
area. Note the colors of the
afterimages relative to the colors of
the original stimuli. Did they appear
different?
Flashing Squares
During the Optical Art
(OpArt) Movement of the
1960s, artists would
create all sort of puzzling
effects with color. For
instance, this "flashing
squares" drawing seems
to wobble and flash
when you concentrate on
one particular area of the
image. How many
squares can you see in
this diagram? Can you
feel the "motion" of the
image?
Flashing Squares
Contrast in Shape
How objects and colors appear is highly dependent on their context. The
structural and spatial variables of a scene can influence appearance and
perception. The following optical illusion demonstrates how we are
sometimes fooled by our eyes.
Instructions: The diagram below features two circles with different
surroundings. Would you believe that the two circles are identical?
How many faces do you see?
This one will make you dizzy. Try focusing on just the
center circle while moving your head.
Which line
connects to line C?
A or B?
What do you see
below?
Look at the grouping of stairs below. How can they keep climbing?
Is this knot pairing of triangles physically possible?
Do you see a rabbit
or a duck?
Despite their appearance, the top lines on each of
these trapezoids is the exact same size!
Can you figure out what this is a picture of?
This image appears to bulge, although it only consists of squares
The gear wheels should appear to SLOWLY rotate. The one on the left side of the
screen
should turn clockwise and the one on the right side of the screen should turn
counter-clockwise
The green is identical throughout this illusion.
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