The document discusses the human eye and vision. It notes that vision is our major sense and half our brain is dedicated to processing visual information. It describes the key parts of the eye including the pupil, iris, retina, and optic nerve. It discusses how the eye inverts images and how rods and cones in the retina detect light and color. The document also briefly mentions stereo vision from having two eyes and the two visual processing channels in the brain.

1. the eye and vision

2. sight
major sense
half our brain dedicated to vision
majority of computer output

3. the eye
what you can see
pupil – the lens covering ‘hole’ into the eye
iris – muscles to change lens shape
behind the scenes
upside down image (lens inverts)
cells to detect light (rods and cones)
optic nerve – blind spot ... filling in

4. sensing light
cones rods
central peripheral
colour (3 kinds) grey only
detail movement
bright light dim light

5. focus and attention
fovea
• centre of vision
• mainly cones
• pretty small => need saccades
peripheral vision
• mainly rods
• detect movement => catch attention

6. onCue
intelligent ‘context sensitive’ toolbar
sits at side of the screen
watches clipboard for cut/copy
suggests useful things to do
with copied date

7. onCue in action
• user selects text
• and copies it to clipboard
• slowly icons fade in
user selects text
20 21
and copies23 to clipboard
22
it
25 24 20 17
7 7 3 7
slowly icons fade in
the dancing histograms very useful a
ing out some of the textile sites yo
x's page at http://www.hiraeth.com/

8. plus ...
two eyes
– stereo vision
– left & right visual fields ‘cross over’
two channels
– old – rapid reactions and primitive responses
– new – conscious vision

9. what we really see
sensation
– direct impact of light on retina
perception
– what we feel we see
not the same – optical illusions

10. Optical Illusions
the Ponzo illusion the Muller Lyer illusion

11. fooled?
optical illusions
– often odd eye positions, unusual images
perception
– designed for the real world
– our brain tries to ‘make sense’ of sensation
for design?