Week 6 - Visual Perception in Pediatric Practice Flashcards
the total process responsible for the reception and interpretation of visual stimuli
visual perception
anatomy in place (development of visual receptive skills)
GA 24
retina and visual cortex (development of visual receptive skills)
GA 24-40
eye movements due to vestibular influence (development of visual receptive skills)
GA 20
some visual fixation, brief reflexive tracking (development of visual receptive skills)
birth
accommodation, convergence, oculomotor subsystems (development of visual receptive skills)
2 months
VMI - grasping and sight (development of visual receptive skills)
4-5 months
smooth, volitional control of eye movements
kindergarten (development of visual receptive skills)
coordinates visual and auditory input (development of visual cognitive skills)
infants
pattern recognition and form constancy can be present how early?
1 week of age (first learn general shape/appearance then details)
the clarity, keenness, or sharpness of vision
acuity
the ability of the eye to change its optical power to maintain a clear image on an object as its distance varies.
accommodation
the ability to merge the images from the two eyes into a single stereoscopic perception
binocular fusion
the coordinated aiming of the eyes while shifting rapidly from one object to another. occurs when visual focus is on a stationary object.
fixation
refers to the continued fixation on a moving object
pursuit/tracking
the rapid change of fixation from one point in the visual field to another
saccadic eye movements/scanning
the turning of the eyes inward toward the medial plane as the object of regard moves toward the observer.
convergence
name 6 behaviors that indicate difficulty with visual acuity.
- squinting
- headache
- eye-ache
- inattention
- takes a while to do something
- avoidance
a condition in which light rays entering the eyes focus in front of the retina, vision is blurred at a distance, but clear at near
myopia
a condition in which vision is blurred and distorted at both distance and near due to oval shape of the eye that cause light rays entering the eye to enter at 2 different points
astigmatism
a condition in which light rays entering the eyes focus behind the retina, and the individual must accommodate to see clearly. requires muscular effort - the amount of effort is greater when the individual looks near.
hyperopia
acuity less than 20/20 that cannot be attributed to refractive error or eye disease. called lazy eye
amblyopia
name 2 behaviors that indicate difficulty with visual fixation.
- difficulty starting at the first word on a page
- inattention
name the 4 components of an OT clinical vision assessment.
- observation of child’s behavior during functional activities - head/postural deviations, do they make eye contact? do their eyes wander?
- history and child interview
- formal eval.
the space or range within which objects are visible to the immobile eyes at a given time
visual fields
describe a test that assesses a child’s visual fields.
- have the child look forward to an object
- have a moveable target move from the back of the child’s head to the front of their face
- ask the parents when they can see the objects without moving their eyes or head
- test each eye
describe the accommodation response test.
- 2 targets are held in front of the child, one target 18 inches from the child’s face and the other target at the child’s CNP
- ask the child to look quickly from one target to other target
describe an assessment that tests pursuits.
- the child is asked to follow a moving target that is 12-16 inches from the child’s face
- assess in horizontal, vertical, and diagonal planes
- eyes should be tested separately then together
describe an assessment that tests saccades.
- child is asked to look back and forth repeatedly btwn 2 targets (8-10 inches apart). the targets should be approx. 12 inches in front of the child’s face.
- assess in horizontal, vertical, and diagonal planes
what does the saccades assessment test?
direct observation for overshooting or undershooting
describe an assessment that tests for convergence.
- the child is asked to keep looking at a target that is held 18 inches from the eyes
- the target is moved slowly toward the eyes
- once the eyes break off or double vision occurs, slowly move the target away from the child until the eyes converge again.
what is normal CNP? what is the break off point?
normal CNP = 3-4 inches
break off point = 4-6 inches
the ability to attend to visual stimuli (alertness, selective attention, vigilance, and divided attention)
visual attention
involves integrating visual processing information with past experiences (both long-term and short-term)
visual memory
ability to detect distinctive features of a visual stimulus and to distinguish whether the stimulus is different from or the same as others. (object perception and spatial perception)
visual discrimination
then necessary visual cognitive component that allows children to picture people, ideas, and objects in their mind’s eyes. essential to reading comprehension and in planning, problem-solving, and organizational skills
visual imagery/visualization
the ability to note key features of a stimulus and relate them to memory
recognition
the ability to note the similarities among visual stimuli
matching
the ability mentally to determine a quality or category by which similarities or differences can be noted
categorization
necessary to interact with and organize the environment (children’s awareness of their body - right/left, up/down, and front/back)
visual spatial skills
left/right
laterality
the understanding of an external object’s position in space in relation to themselves
directionality
name the 3 aspects of visual analysis skills.
- form constancy
- visual closure
- figure ground discrimination
name the 3 aspects of visual analysis skills.
- form constancy
- visual closure
- figure ground discrimination
name the 3 aspects of visual analysis skills.
- form constancy
- visual closure
- figure ground discrimination
ability to integrate visual information processing skills with fine motor movement
visual motor integration skills
ability to integrate visual information processing skills with fine motor movement
visual motor integration skills
the ability to perceive an object’s position in space relative to oneself and the direction in which it is turned; discrimination of reversals and the rotations of figure
position in space
the ability to perceive the position of two or more objects in relation to the body and in relation to each other; the understanding of directions, such as above/below, right/left, and on/off
spatial relations
- the visual ability to perceive the world in three dimensions, enabling determination of the relative distance btwn objects, figures, or landmarks.
- awareness of how far away something is
- helps to move in space (ex: walking downstairs or catching a ball)
depth perception
- the determination and connection of the location of objects and the route to the location
- children’s ability to find their way depends on a cognitive map of the environment.
topographic orientation
- recognition of forms and object as the same in various environments, positions, and sizes.
- the ability to see a form and being able to find that form even though the form may be smaller, larger, rotated, reversed, or hidden.
form constancy
the ability to identify forms or objects from incomplete presentations
visual closure
- the ability to perceive a form visually and to find this form hidden in a conglomerated ground or model.
- enables children to differentiate btwn foreground or background forms and objects.
- the ability to separate essential data from distracting surrounding information
figure-ground discrimination
what is the objective of the hart chart?
to increase the speed and accuracy of saccadic fixation
name 3 underlying skill areas that word searches assess.
- figure ground
- form constancy
- visual closure
name 2 underlying skill areas that mazes assess.
- topographical orientation
- position in space
describe eye movements with straws.
- eyes converge when blowing air
- eyes diverge when sucking out air
