How eyes receptors work, the influence of the light, eyes movements and how human see things. Presentation taken from first chapter of the book "To see, to think, to design. Neuroscience for design" by Riccardo Falcinelli (http://amzn.to/1UgEOkB).

1. DESIGN AND NEUROSCIENCE
#1 - THE EYES

2. PUPIL
SCLERA
The latin pupilla meant doll, because if staring someone straight
in the eye you’ll see yourself reflected small, like a small doll

3. The SCLERA (white part) is visible only in humans but not in animals.

4. Staring for animals is usually taken as a challenge or as a sign of aggressivity.

5. If we’re interested in something the pupil grows larger.
Eyes are an important clue to understand what a person is thinking.

6. An eye with a large pupil is considered more attractive and “good”
than a eye with a small pupil.
Dogs are generally considered good and cats evil because of their pupils. Cats have vertical pupils like snakes (and devils).

7. In 1928 Mickey Mouse was only pupils the icon of cheerfulness
and optimism.

8. In 1939 they introduced the sclera.
Just with two circles more they managed to multiply the psychological possibilities and
the public managed to understand for the first time what Mickey Mouse was thinking.

9. Eyes are like a dark room, Kepler (1571-1630) was the first to discover this.

10. There are many types of eyes, but they were all developed
because of the LIGHT:
an electromagnetic energy which has different wavelengths,
we can see only between 300-700nm.

11. Light is spread in the atmosphere, the beams hitting
parts of matters are scattered in all directions.
Without atmosphere the sky would be black.

12. Shiny surface Opaque surface

13. A porous tile if wet becomes shiny, because the water levels
the thorniness and impose the light to reflect into a unique direction,
so the perceived results is a more intense effect.

14. Pigments do not reflect but absorb the light and release it in different
wave length, that’s the principle of fluerescent paints.

15. The detergets which promise to wash the whitest possible contains some
pigments which goes on the clothes. So the effect is actually the whitest,
not because it’s clean but because the light released by the sheets
is summed to the wave lenght released by the pigment.

16. Before the electricity every artefact was thought for a specific light.
Paintings were designed to work in a particular place with a certain sun exposure.
The icons in a church were designed to shine at the light of the candles, etc.
Galleria Borghese in Rome is one
of the few places where the artworks
are still exposed in the light they
were originally thought for.

17. Books are universal, can stay in every place,
but since they are sold in bookstores,
that’s where the editor choses to invest more.

18. Perception starts when the lights hit the back of the eye, covered by
a membrane called RETINA a dense net of blood vessels.

19. When in photos there are red eyes, it’s because the flash
elighten strongly the retina which is red.

20. CONES
RODS
Details and colours
Brightness scale - greyscale

21. Blue Green Red

22. RODS are more sensitive to short waves (blue-green)
With a dim light reds look darker than blues.

23. CONES are more sensitive to long waves (green and red).
With bright light an azure jumper looks darker and darker as we get more far, till it will look black.
Thing which doens’t happen for an orange jumper.

24. BLIND SPOT

26. IMAGES ARE CREATED BY THE BRAIN,
NOT BY THE EYES.

27. FOVEA is the part with the major number of receptors.

28. The periphery we can barely distinguish and hand in the centre
we can insert a needle.
The pheriphery is more sensitive to the movement than the recognition.

29. The brain elaborate a very small part of the field of view per time,
about the 5%, so we have to move continuosly the eyes.
We don’t see like a camera, we don’t see the whole scene at once.
If we had to see all together we would get way too many information.

30. There are three movements that eyes do:
EYES NEVER STAY STILL
LONG JUMPS
CONSTANT TREMOR
(optokinetic reflex)
SACCADES
FIXATION
}

31. During the saccades movement, no signal is sent to the brain.
You can test this looking in the mirror, you’ll never see the eyes moving.
You only see only the eye in two different positions, like in two movie frames
and like in a movie the movement is illusory.

34. Frog eyes can see the movement but they are blind to still things.
A frog surrounded by dead flies would die of hunger.

35. We need this movement, the tremor to see the things still.
Without that the still thing would disappear to our brain.
In front of the absence of discontinuity or movement information
the brain stops to produce view.

36. EXPERIMENT
Try to stare at an object restraining the impulse to move the eyes
after a while it’s possible to see the ganzfeld (total field).

37. 1995, Bristol, John Findlay find himself in front of a strange case: a girl
looking rotating the head, like a bird..she was born without ocular muscles.
This demonstrate how birds and insects movements are equivalent to our eyes movements.

38. Alfred Yarbus used some contact lenses which reflected on a sensible
surface the eye movement leaving a trace.
From this was possible to see that the eye was moving continuosly on the scene, insisting
on some points which were more relevant.
Simple forms. Relative ocular trace

39. Ilya Repin, An Unexpected Visitor, 1884.

40. Examine the painting freely.

41. Estimate the material circumstances of the family.

42. Assess the ages of the characters.

43. Determine the activities of the family prior to the visitor’s arrival.

44. Remember the characters’ clothes.

45. Surmise how long the “unexpected visitor” had been away.

46. When designing, we should take into account
the physiological basis common to all men, but then we should wonder
WHAT and HOW the other will see.
Adriaen van Utrecht, Still-Life with Hare and Birds on a Ring, 1964