Vision Terms & Visual Perception

Visual perception pyramid

1. Adaptation through vision 2. Visual cognition 3. Visual memory 4. Pattern Recognition 5. Scanning 6. Attention = Alert + Attending 7. Oculomotor, visual acuity, visual fields

vision pyramid

1. Adaption through vision 2. Visual cognition 3. Visual Memory 4. Pattern Recognition 5. Scanning 6. Attention: alert & attending 7. Oculomotor Control

Visual Functions fall under the specific category of the OPTF-IV

1. Domain: Client Factors - Body Function Category - Sensory Function Visual Functions fall under the specific category of sensory function within the more broad Body Function category and under the Client Factors domain

What are some Visual Acuity Interventions?

1. Increase illumination. 2. Increase font size. 3. Increase contrast (color blindness, decrease clutter, visual anchoring) 4. Sensory Compensation 5. Decrease Background Pattern 6. Organization

3 steps to improve visual exploration:

1. Practice making large, quick saccades into blind field. 2. Scan for targets among distractors in systematic way. Teach them scanning strategies. 3. Practice strategies in the real world.

Hemi-inattention vs visual field defect

Hemi-inattention: - Individuals confine their searches to the right side. - Does not attempt or search towards left side - inefficient & more random in search pattern - No rescan/recheck for accuracy - Task is completed quickly VFD: - Search pattern locolized toward the blind side - recognizes & attempts to correct towards blind side - Efficiency in organizing search patterns. - Will check accuracy by rescans - Time spent on task is appropriate based on level of difficulty.

Prefrontal areas

CEO of the brain; prefrontal cortex is critically involved in the emergence of conscious visual perception.

What is the OT role?

DO NOT diagnosing or discerning underlying cause. If the deficit cause a functional limitation and/or related to vision/visual perception. If it is not a functional deficit, you have to rule it out as cognition or vision. Recommend Referrals

What are kind of evaluation and treatment are appropriate for Spatial Relations?

Deficits: understanding spatial concepts, differentiating letters, map reading, finding items, ADLs. Treatment ●Restorative ○Object retrieval using verbal requests ○Describing placement of objects ○Practicing functional tasks ○Orienting to landmarks ●Adaptive ○Organizing env ■Consistency ■Clearly marking areas for important things

noncomitant strabismus

Depends on which directions your eyes are pointed.

Diplopia

Double vision; You can resolve that by just covering one eye.

Strabismus

Misalignment of the eyes, causing one eye to deviate inward (esotropia) towards the nose, or outward (exotropia), while the other eye remains focused

Phoria

Tendency of eyes deviate but you can control it with muscular effort. (convergence)

Fixation

The ability to accurately and steadily gaze at an object; examining details of something.

Saccades

The ability to quickly and accurately look or scan from one object to another (e.g., reading). (Both objects are stagnant) Note: Following an object is "pursuits"..

homonymous hemianopsia

The loss of the right or left half of the field of vision in both eyes.

Posterior parietal lobe

The parietal lobes determine the visual coordinates and plan the visually guided movement of the limbs to pick it up, and the frontal lobes participate in making the choice.

divided attention

concentrating on more than one activity at the same time

Hypotropia strabismus

downward turning of one eye

Oculomotor Control

enables eye movements to be completed quickly and accurately and keeps the image focused on the fovea to ensure that it can be clearly seen. Allows movement of the eye muscles, contraction of the pupils, focusing of the eyes, and position of the upper eyelid (cranial nerve 3 involved)

Binocular Vision

ensures perception of a single image even though the brain receives separate visual images—combines the two together to create one image.

what duty does the Cerebellum responsible for vision?

eyes are landing precisely on a target.

Pursuits

eyes track the object

hyperopia

farsightedness

presbyopia

impaired vision as a result of aging

Stereopsis

inability to perceive depth in relation to the self or in relation to various objects in the environment. ○depth perception (30-40% CVA clients common) (impacts ADLs such as cooking brushing teeth)

Nystagmus

involuntary movement of the eyeballs in an up-and-down (vertical), back-and-forth (horizontal), or rotating direction

Pattern Recognition

involves identifying the salient features of an object and using these features to distinguish the object from its surroundings

estropia strabismus

inward turning of the eye

hemianopsia; hemianopia

lack of vision in half the visual field

amblyopic

lazy eye

Perception

mechanism of the brain that interprets sensory information from the environment.

Visual Memory

mental manipulation of visual info needed for visual cognition; requires ability to retain info for immediate recall or to store for later retrieval

Myopia

nearsightedness

Optometrist

not an MD; diagnose and treat medical conditions and treat vision loss and provide primary eye care (clinical doctor that checks vision and prescribes glasses)

exotropia strabismus

outward turning of the eye

Accommodation

the ability to accurately focus on an object of regard, sustain focusing of the eyes, and change focusing when looking at different distances (ex. maintaining focus when you look up from a textbook to a clock and back to the textbook); Reflex involves vergence system, pupil, & lens.

selective attention

the ability to focus on only one stimulus from among all sensory input

sustained attention

the ability to maintain attention to a selected stimulus for a prolonged period of time

Visual Cognition

the ability to manipulate visual input and integrate vision with other sensory information to gain knowledge, solve problems, formulate plans, and make decisions

Ocular Mobility

the eye's ability to move. (pen light test)

Figure-ground Perception:

the inability to differentiate foreground from background. ex: Seeing a white shirt on a white bedspread. ex: Distinguishing white toothbrush and toothpaste from sink.

Visual Field

the total area in which objects can be seen in the side (peripheral) vision as you focus your eyes on a central point

Hypertropia (strabismus)

upward turning of the eye

Visual Attention

visual processing skill that allows us to notice and focus on detail

Convergence

when your eyes move inward to focus on a nearby object; deficit- double vision

What 3 visual quality functions work together to promote visual awareness of environments at various distances for functioning?

■ Visual Acuity ■ Visual stability ■ Visual field function

What performance skills that would be affected?

○ Processing Skills (initiating, sequening, ect..) ○ Social interaction (turns toward, seeing emotions on the face) ○ Motor Skills (motor planning)

Vision serves as a primary receptor for the following functions:

○Motor ○Cognitive ○Communicative (can't drive) ○Emotions Affects your planning, anticipation, seeking, communication, emotions affects a lot of what you do & how you do it.

Form Discrimination

○The ability to distinguish forms ○Huge part of perception ○Playing a role in your ability to discriminate forms.

Spatial Relations

○process and interpret visual input. Relating what objects are in space. (dressing) ●Localizing object in relation to one another; understanding location of object in relation to self ○Examples: transfers would be hard. Might miss the toilet when they sit down.

●The specific type of visual deficit that occurs after brain injury depends on the area or areas of the brain affected by the injury

○structural damage to the brain ○Damaged pathways that connect brain areas.

What are some interventions for visual field loss?

● Very difficult to Establish/Restore. will be more of an adaptation approach/compensation strategies. - More family education and home evaluation. ●Training saccades for exploration ●Turning the page ●Use a ruler to keep track ●Visual search strategies

Vision Deficits D/T ABI (Acquired brain injury)

●Acuity ●Convergence ●Pursuit ●Quality of Saccade ●Visual Field Loss ●Perceptual Dysfunction ●Strabismus

What are some vision deficits of ABI?

●Acuity ●Convergence ●Pursuit ●Quality of Saccade ●Visual Field Loss ●Perceptual Dysfunction ●Strabismus

What specific visuomotor abilities that should be assessed?

●Acuity ●Fields ●Binocular Vision ○Eye alignment, accommodation ●Oculomotor ○Saccades, smooth pursuits, convergence

What visuomotor abilities needs to be assess?

●Acuity ●Fields ●Binocular Vision ○Eye alignment, accommodation ●Oculomotor ○Saccades, smooth pursuits, convergence

What are kind of evaluation and treatment are appropriate for Figure Ground Perception?

●Assessing ○Ayre's Figure Ground Test (standard) ○Functional Test ■Ask your client to find an object in view ● having the do their ADLs ●Treatment ○occupation -based activities to judge distances, distinguish forms, and separate objects from a surrounding background. ○restore FGP ■ look at a workbook and interpret some blue point drawings. ○Adaptive: Organization and remove clutter.

what control basic visual functions, such as the light (pupillary) reflex, blink response, and accommodation reflex.

●Brainstem and cerebellum

Assessments should include:

●Client interviews ●Vision screenings ○ Visual field optical mobility, visual acuity, visual attention, visual searching. ○ ●Functional clinical observations ●Questionnaires ●Referral as indicated

What are kind of evaluation and treatment are appropriate for form discrimination?

●Damage ○Parietal and temporal lobe ○Attending to subtle form variations is impaired ●Evaluation ○Formboard test (10 forms and client just has to match them) ○Functional test ●Treatment ■ Most are not going to restorative so use tactile cues using adaptations and compensation. Adapting the environment is the going to be impact the most & organization.

What are the muscles controlling the eye?

●Lateral rectus ●Superior rectus ●Superior oblique ●Levator ●Inferior rectus ●Inferior oblique 12 total muscles because 6 for each eye

Ventral Stream (What)

●Object recognition: Milk ●Color: Blue ●Shapes: how big it is. ●Size discrimination

What are the 3 cranial nerves of vision?

●Oculomotor (cranial nerve 3) ●Trochlear (cranial nerve 4) ●Abducens (cranial nerve 6)

What are kind of evaluation and treatment are appropriate for Stereopsis?

●Required to: ○ locate objects ○ Accurately use hand movements under visual guidance. To manipulate. ●Impairment ○Activities that require the judgement of spatial relationships ■EX) Sports, card games, bingo, threading a needle, reading, bird watching, cooking, painting, and eating.

What are some visual scanning Interventions?

●Scanning worksheets ○ Cancellation worksheets ●Scanning strategies ○Find the right wall and scan across until you see the left wall ●Incorporate scanning into functional tasks ○ Incorporate it into an ADL task. "lets clean up your room, finding items" ●Pacing or cuing to control speed of scanning to control impulsive or erratic scanning ○ saying it out loud. ●Organize clothing and task tools in a consistent order

Topographic Orientation

●The ability to situate yourself within a large scale environment; enables navigation, following a familiar route, etc ○supporting that way finding.

what duty does the brainstem responsible for vision?

●Vestibular nerve nuclei. Helps with gaze stability.

Dorsal Stream (Where)

●Visuospatial perception: Beside the Butter ●Detection of movement

Cortical Blindness

●When injury occurs bilaterally around the calcarine fissure ●Usually detect light ●Can detect movement ●Severe visual impairment

what duty does the cortex responsible for vision?

●eye movements to shift attention

What are some interventions for Diplopia?

- Vision training - Scanning activities - Patch Spot patch Partial vision occlusion Prism glasses so they can lay on their back and read.

Near Acuity

A measurement of how well you can see close objects; ability to see objects clearly as they come close to the eye (pedretti); 16 in. measure

Vergence

A type of eye movement in which the two eyes move in opposite directions 1. Convergence: both eyes turn toward the nose 2. Divergence: away from the nose 3. Near point divergence

Occipital lobes

A visual library; sort through information that comes in. where the Primary visual cortex is going to be.

What is the ultimate function of vision?

ADLs, balance, support that participation in the daily activities.

Vergence

Ability to accurately aim the eyes track and brings it towards you.

Posterior temporal lobe

Integrates visual and auditory input for language comprehension. Damage to the temporal lobes can result in impaired recognition, problems with route finding and poor visual memory.

Ophthalmologist

MD; treats diseases that cause visual impairments of the eyes (ie. Macular degeneration)

Smooth Pursuits

Much slower tracking movements of the eye designed to keep a moving stimulus on the fovea; allows you to track moving objects

Presbyopia

Natural decline of accommodative ability due to age.

Difference between hemianopsia(visual field defect) vs. visual neglect.

Visual field deficit is not physically seeing everything although initiation is normal from left to right search pattern. Visual neglect is where the client exaggerate inattention towards one half and do not move their eyes past midline.

Oculomotor Dysfunction

Visual impairment characterized by lack of efficient eye movements and eye-tracking skills. functional deficits may include difficulties with: reading speed copying skills writing skills, smooth pursuits, convergences

astigmatism

a mix of both far & nearsightness

Visual Acuity

ability of the eye to distinguish shapes and the details of objects to a given distance, clarity and sharpness of images

alternating attention

ability to alternate attention back and forth between stimuli

Visual Perception

ability to interpret/ perceive our surroundings through the light that enters our eyes

Distance Acuity

ability to see objects at a distance; 20 ft measure; ex) Snellen Chart

R/L Discrimination

ability to use/ apply concepts of left and right (cane on left side or mobility.)

Vergence system

align the eyes to maintain binocular system and vision.

Comitant strabismus

always going to be the same no what way she looks. It's going to stay misalign

Visual Fields

area of the visual system that allows for an individual to orient to specific spatial areas

Metacognition

awareness and understanding of one's own thought processes.