Vision and Visual Perception Evaluation and Intervention Flashcards
Acuity
Capacity to discriminate fine details of objects in the visual field (20/20).
Bring the object into a nearer point of vision where it is the clearest/sharpest.
This requires accommodation reflex
Clarity of vision- what most people need corrective lenses for
Sight-
the ability to discriminate small objects, such as in acuity
Vision-
the process of taking in, processing and integrating visual and other sensory information to form a perception
Optometric model of vision:
- acuity, refraction and eye health
- visual efficiency skills
- visual information processing
Visual Receptive Skills
foundation of visual cognitive functions
Visual Integrity - 3 parts
Acuity
Refractive abilities
Eye Health
Visual efficiency - 3 parts
Accommodation
Binocular vision
Ocular motility
3 part of Visual Cognitive Skills
Visual Attention
Visual Memory
Visual Perception
Visual Perception
is what is happening in the brain, the child’s ability to use visual information to make meaning of what they see
When learning letters a child must
be able to
- recognize
- recall what a letter looks like
- discriminate between two familiar letters such as “b” and “p”.
- Think of the visual version of the alphabetic system
Difficulties in this area visual perception:
refer for formal testing with a developmental optometrist and/or occupational therapist
3 part of Visual Perception- Form Perception
Form constancy
Visual closure
Figure ground
spatial perception
depth perception - how far or close something is
topographic orientation - you know the layout without having to physically see it.
visual spatial orientation - ability to write on the line or appropriate spaces.
Visual Motor Integration
Combines visual perceptual and motor skills
Using vision to guide motor output.
Child’s ability to copy
shapes, letters or numbers.
For the preschooler entails drawing lines to join objects.
More advanced examples of this skill involve copying cursive letters accurately.
when is vision developed
first 2-3 weeks
senses that are learned in the first 2-3 weeks.
infant’s world is learned through the senses of smell, taste, touch and sound with mother’s voice (cadence & sound) “recognized”
proprioception (including vestibular system) from being moved around for diaper changes, baths, dressing and lots of TLC.
visual motor learning coordination 3-4 weeks
vision and hearing supersedes other senses as the most important learning channels
Vision Leads The Development Of Integrative Functions
Visual-Motor Learning and Coordination:
Four to twelve weeks:
Once head control is achieved, including rotation and vertical movements
Visual “grasping” of objects in space stimulates all motor functions
This initiates the drive to retrieve them.
Rolling over may occur initially while trying to get a toy or see an object of interest.
Visual-Motor Learning and Coordination:
Six months onward:
Rolling over and raising up on upper limbs
Pushing back or forwards
Eventually sitting, crawling, creeping, cruising and walking
All believed to be drive initially by visual stimulation of something in the environment, coupled with the desire to obtain objects, bring them to midline for exploration and manipulation and thus learn about them.
almost all behavior is visually driven throughout life, including all movements, reading, writing, math, inventing, discovering and creating.
True
Vision Leads The Development Of Integrative Functions
Visual-Manual (eye-hand) Coordination:
Begins around three months when hands meet in midline and infant studies movements.
Helps develop concepts of body parts, sense of self and space in relation to midline activities. This is reinforced by seeing objects (or hearing sounds) at a distance or up close.
Vision Leads The Development Of Integrative Functions
Visual-Manual-Oral Coordination: (Visual-Motor-Oral Triad)
Begins around 3-months with grasping bottle and holding it, along with reaching grasping coordination.
Visual-manual-oral coordination or “triad” improves over first year
Vision Leads The Development Of Integrative Functions
Visual-Object Recognition and Learning:
Begins around two to three months with recognition of parent’s face and later midline study of hands and toys.
All reinforces concepts of stereognosis coupled with stereoptics, and midline activities or body movements.
Vision Leads The Development Of Integrative Functions
Visual-Spatial Recognition and Learning:
Begins early; by 4 months infant can follow activities going on in visual surround.
6 months infant searching out surroundings for familiar versus strange voices, sounds or objects
Concept of object-constancy in relation to objects and space developing by 6-10 months
In C.V.I and blind infants both visual-object and visual-spatial recognition and learning, including concept of object-constancy, are severely impaired.
Impact on School Performance
Play - social aspect of play
Self-care - dressing, eating,
Education - math, reading, writing
Informal assessments for vision
quick vision screen
queensbury vision screen
Cornell vision assessment
Formal assessment for vision
Beery-Buktenica development rest of visual motor integration, age 2-100, Subtests include:
Visual Motor Integration
Visual Perception
Motor Coordination
Developmental test of visual perception (DTVP-3). Age 4-12:11, 30 minutes to administer. Subtests: Eye Hand Coordination
Copying, Figure Ground, Visual, Closure, Form Constancy
Test of Visual Perceptual Skills (TVPS), Age: 5-21, Time to administer: 25 minutes
Subtest:
Visual Discrimination
Visual Memory
Spatial Relationships
Form Constancy
Sequential Memory
Visual Figure-Ground
Visual Closure
Motor- Free Visual Perception Test
Age: 4-95, Time to administer: 20-25 minutes
Subtests:
Visual Discrimination
Spatial Relationships
Visual Memory
Figure Ground
Visual Closure
Intervention for vision
Sensory Processin
- Provide age appropriate activities with tactile, auditory, proprioceptive and vestibular input.
- Firm touch is generally less noxious
- Use of verbal cues prior to input
Intervention for School Based Skills
Maximize tactile discrimination
Opportunities to explore real-life objects.
Provide opportunities to practice in-hand manipulation skills.
Intervention
Strengthen Cognitive Skills
Concepts that cannot be touched or heard need to be described and explained
Help to distinguish and identify sounds
Self-generation of strategies
CORTICAL VISUAL Impairment
CVI defined: Bilateral Visual Loss with normal pupillary responses (which are brain stem responses) and lacking obvious eye abnormalities. In other words the anterior components of the visual system are intact but the posterior components are compromised
CVI Causes:
Any process that damages the visual parts of the brain. Examples include:
●Brain damage from prematurity
●Stroke
●Decreased blood supply and/or decreased oxygenation
●Brain malformation or infection
●Hydrocephalus (increased pressure in the brain)
●Seizure
●Metabolic disease
●Infection
●Head trauma
Neurologic disorders
CVI Typically Demonstrates:
Color Preference
●Need for Movement
●Visual Latency
●Visual Field Preference
●Difficulty with Visual Complexity
Light Gazing and Non-purposeful Gaze
●Difficulty with Distance Viewing
●Atypical Visual Reflexes
●Difficulty with visual novelty
●Absence of visually Guided Reach
CVI Intervention Strategies
Use of a black background
●Bold colors (yellow and red are preferred colors)
●Make a calm and uncluttered work environment that nurtures learning
●Use predictable outcomes in class with lots of routine
●Give extra time, repetition, and show patience
●Give few choices and slow to introduce novelty
●Simple directions
●Allow for breaks, especially visual breaks
●It’s ok if they are not looking at you, as long as they are listening
●Use dark font that is larger and less cluttered
Retinopathy of Prematurity
- Seen in extreme premature birth
- Retina and visual cortex mature in last trimester, therefore, when born prior, visual deficits may occur
- Visual fixation as an issue
- Neonatal care and ophthalmic care improve outcomes
Retinopathy of Prematurity Case study
Consider development
Education for family
School needs
Physical
Social
Self-care
Promote independence
Think of theoretical foundations!
Vision experts
Optician- fit and sell prescription glasses and contacts after the prescription has been obtained. They cannot perform medical or vision exams.
Optometrist- can examine eyes for vision or medical problems (i.e. glaucoma, cataracts) and prescribe glasses and contacts. They cannot perform surgery or prescribe medication (in some states).
Ophthalmologist- can prescribe glasses/contacts; perform eye-related surgical or medical procedures. They cannot fit or fix frames.
