The presentation focuses on the vision of colours, what the primary colours are and what their meanings are. It also briefly describes how humans and animals see. A few human vision impairment conditions are introduced, too. The last slides present information on how mammals, birds and reptiles see. #SciChallenge2017

1. ColourVision
#SciChallenge2017
Created by: Zsofia Obracz-Nagy, Virag Kiss
Teacher: Andrea Jozanne Kamuti
TancsicsMihaly Elementary School, Cegled, Hungary – www.ctmi.hu
Principal: Gabor Rimoczi

2. What is Colour Vision?
Living beings are able to
distinguish objects by means of
the wavelength of the light that
they reflect, emit or transmit.

3. The Human Colour Vision
Colour is a quality constructed
by the visual brain and not a
property of objects.
A 'red' apple does not emit red
light. Rather, it simply absorbs
all the frequencies of visible
light shining on it except for a
group of frequencies that are
reflected and which are
perceived as red.

4. Newton and the Colour Spectrum
Isaac Newton was the first to understand the
rainbow: he refracted white light with a prism,
resolving it into its component colors: red, orange,
yellow, green, blue and violet.
He created a conceptual arrangement of colors
around the circumference of a circle which
became the model for many colour systems of the
18th and 19th centuries.

5. Meaning of Primary Colours
Green
Since the beginning of time, green has
signified growth, rebirth, and fertility.
Today it is the symbol of ecology and
the environment.
Red
Red is the color of extremes. It’s the
color of passionate love, seduction,
violence, danger, anger, and
adventure. Red is the color of good
luck in Asia and is the most popular
color in China.
Blue
Blue is nature’s colour for water and
sky, but is rarely found in fruits and
vegetables. Today, blue is embraced
as the color of heaven and authority,
denim jeans and corporate logos.

6. Colour Constancy
Colour constancy is the ability to perceive colours of objects, invariant to the
colour of the light source. A green apple for instance looks green to us at
midday, when the main illumination is white sunlight, and also at sunset,
when the main illumination is red.

7. Visual Disorders

8. Night Blindness
People with night blindness experience poor vision at night or in dimly
lit environments. Night blindness caused by nearsightedness,
cataracts, or vitamin A deficiency is treatable. You can’t prevent night
blindness that’s the result of birth defects or genetic conditions, such
as Usher syndrome.

9. Cataract
A cataract is a clouding of the lens
in the eye that affects vision. Most
cataracts are related to aging.
Cataracts are very common in
older people.
In a normal eye, light passes
through the transparent lens to
the retina. The lens must be clear
for the retina to receive a sharp
image. If the lens is cloudy from a
cataract, the image you see will
be blurred.

10. Glaucoma
Glaucoma is a group of
diseases that can damage
the eye’s optic nerve and
result in vision loss and
blindness.

11. Blindness
Blindness is the inability to see anything. People can become blind
because of diseases or accidents, but sometimes people are born blind.
When people are blind they use such things as the alphabet in braille
and guide dogs to do every day life things.

12. Partial Vision Loss
Most partially blind people
can sense light. Partial
vision aids, such as
magnifying equipment and
Closed Circuit Television are
important tools that make
life easier for partially
sighted persons.

13. Vision of the Animals

14. Birds
Compared with many mammals, humans and primates have relatively
good color vision, because most others have only two cone types,
which must be like having only two color channels on a television.
Compared with that of birds it is rather poor, because they have four
single-cone types: red, green, blue, and ultraviolet (UV). Not only do
birds have more types of cones, they have more of them. What’s more,
birds’ cone cells contain a colored oil droplet, which may allow them to
distinguish even more colors.

15. Fish
Birds and mammals (including
humans) normally adjust focus by
changing the shape of their lens, but
fish normally adjust focus by moving
the lens closer to or further from the
retina.
Some fish can see ultraviolet and some
are sensitive to polarized light.
Fish vision shows evolutionary
adaptation to their visual environment,
for example deep sea fish have eyes
suited to the dark environment.

16. Reptiles
Reptiles’ vision is typically adapted to
daylight conditions, with colour vision
and more advanced visual depth
perception than in most mammals. In
some species, such as blind snakes,
vision is reduced.
Some snakes have extra sets of visual
organs in the form of pits sensitive to
infrared radiation (heat).

17. Insects
Arthropod eyes are called
compound eyes because they
are made up of repeating units,
the ommatidia, each of which
functions as a separate visual
receptor.
The compound eye is excellent
at detecting motion.
Some insects are able to
distinguish colors.

18. Mammals
Mammals normally have a pair of
eyes.
In many animals, including humans,
eyelids wipe the eye and prevent
dehydration. They spread tears on
the eyes, which contains substances
which help fight bacterial infection as
part of the immune system.
In many animals, including humans,
eyelashes prevent fine particles from
entering the eye.

19. Sources
• http://gurneyjourney.blogspot.hu/2010_02_01_archive.html
• https://simple.wikipedia.org/wiki/Colour_vision
• https://www.mozaweb.hu/Lecke-MOZ-A_feny-Az_allatok_szinlatasa-99635
• http://www.webexhibits.org/colorart/bh.html
• https://www.colormatters.com/the-meanings-of-colors
• http://colorconstancy.com/
• http://www.healthline.com
• https://nei.nih.gov/health/
• https://en.wikipedia.org/wiki/Visual_impairment
• http://www.audubon.org/magazine/may-june-2013/what-makes-bird-vision-so-
cool
• https://en.wikipedia.org/wiki/Vision_in_fishes
• https://en.wikipedia.org/wiki/Reptile#Vision
• https://en.wikipedia.org/wiki/Mammalian_eye