this was a group presentation done by Sport Science Students in Unizul The presentation looks at the eye as one of the five sensors and as a skill(visual skills).

1. THE PROCESS
OF SENSATION

2. 
Sensory receptors that are sensitive to various kinds of energy in the environment. It would be impossible for
you to relate in any way to any movement situation without these receptors to collect this energy and translate
it into nerve impulses that are carried to your brain .
 Photoreceptors - Respond to light , found in the retina
 Mechanoreceptors - Found in skin
 Nocireceptors - Respond to pain , found in nerve ending throughout the skin
 Thermoreceptors – Found in skin ,sensitive to cool or warm temperature
 Chemoreceptors - located in the nose and tongue, respond to chemical stimulation
 Each of these receptors has its own unique structure and a special way of functioning and the sensory
neurons from these receptors all deliver coded messages to the central nervous system
 Coded messages – interpreted to form a perception of a situation

3. 
Structure of Visual System
• Eyes are primary structures of
visual system
• Eyelids protect them and
continuous lubrication prevents
them from drying out
• Six muscles assist the eye to
rotate within its socket
• Purpose – scan the environment
quickly to gather information
• Photoreceptor stimulation occurs
when light hits an image in the
environment

4. 
 Receptor Cells:
• Rods and Cones – Contain chemical which
reacts to light stimulation
• Rods do not require much light to stimulate
them while the Cones do require substantial
light
• Cones are responsible for the perception of
colour and detail while Rods support vision
in dim light and detection of motion

5. 
Functions of :
• Fovea – Back of the eye
where there is high
concentration of cones
• Provides best visual
information if your head
and eyes are positioned
correctly
• Blind Spot – Spot where
nerve fibers from the
receptors of the retina
converge
• Optic nerve will be
formed from the
convergence and will
transport all coded
messages
• No vision is possible
when an image hits the
blind spot because there
are neither rods or
cones on that spot

6. 

7. 
 Vision is a combination of
Physiological and psychological
Processes
 Optic Array - Patterns of stimulation that
reflected light makes on your retina .It is
literally what you can see and it is
important
 Optic array creates a stable picture
How Vision Works

8. 
 Optic Flow – The changes
in optic array
 Optic flow has direction ,
speed and size
 It is used by the brain to
determine direction and speed
and motion

9.  Static Visual Acuity – Ability to
see and identify objects
correctly, best achieved by the
ability to focus on the image of
the object on your fovea. You
must learn to suppress parts in
the background that will distract
you from forming a perception
of the situation
 Dynamic Visual Acuity – Ability
to see and identify an object in
motion or if you are in motion .
The ability to pursue – focus on
an object and track it as it or you
move
Visual Skills

10.  Rotation – tracking the object as it
moves in slow motion , allowing
you to lock and hold focus on the
object while gathering information
about it
 Saccadic – When the object moves
quickly. Eyes will focus on the
object then jump ahead to meet the
object further on its pathway then
focus quickly on it and then jump
again
Tracking: Rotation and Saccadic Eye
Movement

11. 
 Ability to change your
focus from near to far
objects then back
again, allowing you to
adjust your eyes to see
objects clearly at
varying distance
Accommodation

12.  Convergence – ability to focus both
of your eyes on the same object and
hold the focus as objects moves
forward or away from you
 Divergence- ability to focus both of
your eyes on the same object and
hold the focus as the objects moves
towards you or you move away from
it
Convergence/Divergence

13.  What you can see in the
parts of the optic array that
falls out of your foveal focus
 Higher and wider your
peripheral vision, wider
and higher your optical
array
Peripheral Vision

14.  Ability to judge
accurately the size of
different object that are
varying distance away
from you
 Involves recognition that
objects maintain a
constant size even from
afar
 Constancy – involves the
perception of a space
between two objects as
constant
Perception of Size Constancy

15.  Ability that allows you to
focus on an object (figure)
that is embedded in a
distracting background (
ground)
Perception of Figure and Ground

16. 
 Ability that allows you to separate and
focus on parts of a whole image in an
environment eg: Arm action and point
of ball contact when opponent serves
you the ball in Tennis
 This ability also allows you to picture a
whole , based only on seeing parts eg
when you see opponent drive towards
the basket in basketball and based on
what you saw , it is not the beginning
of his lay up shot
Perception of Whole and Parts

17. 
 Ability to accurately judge
where things and people are in
the environment in relation to
you
 Laterality – your sense of what
is left and right
Spatial Orientation

18. 
 Ability to see objects as three
dimensional , allowing you to
judge accurately :
 - Their size
 How far from you they are
 Distance between them
Depth Perception

19.  Type of perceptual ability to judge when
a traveling object is going to arrive at a
certain point in space , allowing you to
intercept or dodge any object
Coincident Timing

20. 
 Ability to remember what you have
seen
 Emotional value you put in on a
situation may make it easier to
remember
Visual Memory

21. 
 Ability to picture or imagine something
in your mind .
 Visualize yourself doing something or
something happening with you taking
the role of an observer
 Not always categorized as perceptual
ability
 Requires activation of your visual cortex
because you create an image in your
mind when you visualize
Visualization