The Early Years: Strategies and Resources for working with very young visually impaired children
Presented on Thursday 6 March 2008
Sequence of Visual Development
Janis Sugden, SSC; Chartered Teacher Vision Services Clackmannanshire
Vision
"Vision is our main co-ordinating sense"
It helps us to understand our world and what is happening around us.
"Over 40% of the brain is devoted to vision. It is important
to recognise that the reason that so much brain tissue is devoted to
visual function is that our understanding, interpretation and movement
through the visual world is a very complex process"
"It is the brain that sees"
Professor Dutton 1997
- It is essential to make a distinction between eyesight and vision.
- Eyesight = visual acuity, which means how clearly we can see.
- Vision = "guiding mechanism in the growth and
development of learning ... getting information in what you do with what
you see"
Dr Joel Zaba, Optometrist and consultant to Education Vision exercises
Vision: Video A
- Sequence of Visual Development Birth
- Corneal reflex to touch
- Pupil reaction to light
- Reflex closing of both eyelids to bright light shown in face. Lids will tighten during sleep
- Saccadic system present at birth
- Cries real tears
- Prefers human face to other forms of stimulus
One to two weeks
- Rudimentary fixation on objects.
- May use only one eye at a time
- Fixates on facial expressions; may imitate
- Prefers contours, vertical and horizontal edges, larger sizes, simple patterns.
One to three months
- Nystagmus induced by vestibular stimulation
- Stares at light source
- Follows moving objects, to midline first, then past midline
- Fascinated by bright lights and bright colours
- Advancing fixation ability emerging convergence as close as 5 inches
- Binocular coordination
- Begins to look within designs, instead of fixing on one spot along the perimeter
- Hand regard, usually to side favoured by tonic reflex
- Swiping may occur on favoured side
- Vertical gaze movements emerging
- Shift eyes toward sound sources
Three to five months
- Has stereo vision
- Fixates on objects at three feet
- Macular development at its peak
- Peripheral vision poor; field is only about one third adult's
- Advancing inspection of hands
- Central vision
- Emerging accommodation at distance of 5 to 20 inches
- Alternate gaze from hand to object and from object to object (rapid movement)
- Has colour vision
- Peripheral vision
- Has depth perception
- Preference for novel patterns begins to emerge
Five to seven months
- Eye to hand coordination developed 'top level reaching'
- Fixation fully developed
- Discrimination of forms
- Convergence occurs consistently
- Most binocular reflexes coordinated
- Responds differentially to facial expressions
- Begins to demonstrate visual memory
- Interest in tiny objects
- Tilts head to look up
- Smooth visual pursuit (follows with eyes and not necessarily head)
- Emerging depth perception
- Interest in shapes
- Visual pursuit is erratic: actually uses saccadic eye movements
The importance of being one
- Eyes and head move together
- Interest in shape sorters
- Tracking
- Interest in pictures
Twelve to eighteen months
- Identifies likenesses and differences
- Interest in pictures
- Marks and scribbles
- Vertical orientation develops
- Demonstrates 20/20 acuity by 18 months
The importance of being two
- Scanning, fixing, tracking
- Language becomes important to help point out likenesses and differences
Between 18 months and 3 years
- All accommodation develops
- Visual image recalled
- Myelinisation of anterior visual pathways complete by 24 months
Vision
True creativity, understanding and efficient learning occurs when we use the left and right halves of the brain together.
The importance of being three
- Eye movements and ball skills
- 4c's compare, categorise, comprehend and communicate
- Between three to four years
- Copies geometric figures
- Eye-hand coordination good
The Intellectual development of the child
Acknowledgements (and further reading)
Sequence of Visual Development adapted from Preschool Visual Stimulation: It's more than just a Flashlight! Lois Harrell and Nancy Akeson, American Foundation for the Blind.
Videos Zoom Resource, c/o Zoom Learning, PO Box 13889 Edinburgh EH15 2WH
Exercises and activities Movements and Learning the Children's Song Book and music CD. Brendon O'Hara.