eye Flashcards
pupil
small opening in centre or iris
cornea
transparent covering that bends light rays into pupil
iris
coloured, circular muscle
dilates.contracts to regulate entering ligth
lens
disc that flattens to see distance + bulges fro close images.
refracts light onto the retina
presbyopia
old eyes
retina
thin light sensitive membrane containing photoreceptors (rod/cones)
images projected upside down and reversed
rods
black, white, grey (120mil)
cones
colour, fine detail. need light (6mil)
fovea
clearest vision (30k cones)
rods and cones do what with light waves
transduce light waves via the optic nerve to the occipital love
why do we have a blind spot
no rods/cones, optic nerve
sun blindness
dark adaptation gradual - rods adjust slowly
light adaptation quick - cones adjust quickly
hyperopia/farsighted
distance from the lens to the retina is too short
myopia/nearsighted
distance form the lens is too long
emmetropia
distance from the lens to the retina is appropriate, normal
three dimensions to the colour we experience
hue - colour
saturation - purity
brightness - intensity
young-helmholtz TRICHROMATIC theory
retina contains three types of colour receptors:
RED GREEN BLUE
opponent-process theory
opposing retinal processes enable colour vision
red-green
yelloe-blue
white-black
trichromats
see + perceive 3 primary colours
dichromats
partially colour blind
monochromats
can’t see colour
feature detectors
nerve cells that respond to specific features or stimulus
shape, angles, movement
feature detectors and supercells provide what
instant analyses of objects in the world around people
parallel processing
processing many aspects of a problem/scene simultaneously
brain integrates parts (binding) into a whole perceived image
consequences to damage to neural networks (parallel processing)
damage to neural networks may render a person unable to perceive moment, form, depth, colour
form perception - figure ground
objects stand out from surroundings
for perception - grouping
organize stimuli into meaningful groups (similarity, proximity, continuity, closure)
BINOCULAR DEPTH CUES
each eye sees in two dimensions, together n=both eyes see 3D
retinal disparity
distance. closer object = more disparity
types of perceptual constancy
size (as images grow/shrink our brain understands distance)
shape
brightness
colour
real vs apparent motion
real - perception of moving when something else moves
apparent - phi phenomenon, sequence of lights moving, autogenetic illusion
bottom up processing
UNFAMILIAR
- individual bits processed as a whole
top-down processing
FAMILIAR
- experience, knowledge + context influence perception
- our perceptual set (green ice cream)
