Sense of sight
Your eyes are your most important sensory organ. They are the only
located visibly on your body’s surface.
“Seeing” is often used synonymously
for “observing” or
“understanding”. Yet in actual fact, your eyes only
colours and light and dark. You can see shapes, motion and proportions
because your eyes move and work together with the senses of movement
It is easier to block visual stimuli than smells or tastes. There is a
between you and what you see and thus you observe more consciously. Of
all your senses, sight contributes most to your awareness. You are an
organism with conscious thought,
which is intricately involved with the act of seeing. This also means
that it is easier to be mistaken about
what you see than what you smell, for example. Sometimes, your thoughts
determine what you see. You
can experience this in two of the exercises, below.
The sense of sight is the most popular sense for scientific
observation. Everything is expressed visually,
often in numbers, because the eyes are supposed more reliable than
other, ‘more primitive’ senses such as
smell and taste. The eyes are considered to be objective.
The eye is a transparent oval ball into which light enters. Light rays
first pass through the
cornea and then through the pupil. The pupil detracts and expands,
depending on how little or how much
light there is. The pupil is located in the centre of the iris. After
passing through the pupil, the light is
concentrated by the lens, it passes through the eyeball and falls onto
the retina. The retina has conical
and rod-shaped receptors.
through the eye
The eyeball is made up of a transparent, colourless, jellylike
substance containing 99% water. The tissue
of the cornea has a somewhat crystalloid structure. The rod-shaped
photo-receptors on the retina (pars
optica) can sense light and dark, while the conical-shaped receptors
(pars caeca) are sensitive to colours.
The pars optica adapt very well to changes in the degree of light, as
you will have experienced on
entering a darkened room. First you see nothing, but after a while you
can see quite a lot and find your
way around. You cannot see colours in the dark. The yellow spot is the
most sensitive part of the retina
and is made up solely of pars caeca. The place where the bundled
optical nerve leaves the eye is called
the blind spot, as the eye has no receptors to register anything here.
Most people can see about 150 colours, though some can see more. We can
perceive the subtlest
differences in the colour green. Colours can affect your mood. Red
makes people active. It is perceived as
being lively and restless, and boosts strength and energy. Orange makes
people enthusiastic, while yellow
radiates and gives a sense of cheer. Green is restful and balanced.
Blue is a cool colour and stimulates
thought. White is the reflection of the spirit; it gives us a sense of
purity and symbolises chastity . Black,
on the other hand, evokes human sorrow.
A rainbow: red at
the dark side, blue at the light side
Goethe discovered that colours are a result of the play between light
and dark. You see red, orange and
yellow when you look out of the dark at something light, the sunset for
instance. Blue and violet
predominate when you look from the light at something dark. That is why
the sky is blue: it is light here
on earth, but black in space.
Goethe put it this way: light’s victory over darkness results
in active colours (red, orange and yellow),
while the victory of darkness over light brings out passive colours
(blue, indigo and violet). You can verify
this by looking at a rainbow. The sky is always darker at the top of
the rainbow than at the bottom, and
the red is always on top where it is darker, and the violet on the
bottom, where it is lighter. You can find
evidence for this rule in brown eyes, where the iris is red nearest the
pupil, and green or bluish nearest the
white of the eye.
Colours are arranged on a colour wheel in a succession of red, orange,
yellow, green, blue, indigo, violet,
then back to red and so on. Only colour can be arranged in a circle, it
does not work with other
A colour circle
When you stare at a colour intensely for a while and then look away,
you will see an after-image, an
image whose colour is the opposite, or the complement (on the colour
wheel), of the original. For
example, if you stare at a violet-red object for a minute, you will see
an after-image made up of green
and blue, since green complements violet and blue complements red.
During prolonged exposure to a
bright colour, the conical receptors on the retina that perceive the
colour become desensitised. The
negative after-image occurs during the recovery of the desensitised
retina. The colour of the after-image is
not a physical, material colour; rather, it has a lingering, unearthly
and transparent quality. You could
describe it as an etheric colour.
The effect of colours on mood has been demonstrated effectively in
scientific experiments such as the
following. The subjects in this experiment did not know what the
purpose of the experiment was. One half
of the group was told to paint a certain picture with red paint, while
the other half was told to paint the
same picture with blue paint. After fifteen minutes of painting, the
group using red paint was louder and
more restless than the group using blue paint. This experiment showed
how mood was affected by these
Another experiment was carried out in a factory. One room in the
factory was painted in the usual colours
and the other in soft, human tones. Before long, workers in the second
room had achieved a 15% higher
production rate and taken 30% less sick leave than those in the first
Observe the two objects below. What do you see? What else can you see?
Can you change your
focus from one observation to the other? Then what do you experience?
Look at this picture, what do you see?
Place a coloured sheet on top of a white piece of paper. Stare at the
coloured sheet for a minute,
then remove it and continue staring at the white paper. What colour do
you see now? What
qualities would you ascribe to this colour, compared to the coloured
sheet? Do this exercise for each
of the colours of the rainbow and find their complementary colours, or
Painting exercise: paint something in one colour. After half an hour,
see what sort of mood you are
in. It is better to do this exercise with a partner: let one person do
the painting while the other
observes the painter.
Again, what do you see? If you are part colour blind then you
will not see the numbers.