Human Occ: Chap. 8 M&W Vision

Chapter Questions

Question 1:

Based on the above information, Chuck may have difficulty with completing which of the following daily tasks?
Correct Answer:
B. Shaving the left side of his face
✅ Because Chuck has a left visual field deficit, he may not see or notice that he did not shave the left side.

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Question 2:

The occupational therapist has delegated to you to perform a quick, objective visual assessment of his HH severity. Which assessment would be most appropriate to quickly assess his HH?
Correct Answer:
B. Have Chuck cross out all the “A’s” on a sheet filled with random letters
✅ This provides a fast, objective measure of his visual field and can be retested to monitor progress.

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Question 3:

During a recent therapy session, Chuck asked how soon his vision will return to normal so he can return to work. What is the best approach to take with Chuck when answering this question?
Correct Answer:
B. Communicate to Chuck that it is too soon to tell
✅ This is truthful and acknowledges that recovery from HH varies widely.

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Question 4:

How can HH impair his safety in the home?
Correct Answer:
A. He may be unaware of hazards on his left
✅ For example, he may not see a step, a stove burner, or other hazards on his left side.

The Vision Treatment Team

Ophthalmologist

• Medical doctor (MD) specializing in eye health and diseases

• Diagnoses and treats eye conditions like cataracts, glaucoma, macular degeneration

• Performs surgical procedures related to the eyes

Neuro-ophthalmologist

• MD with training in both neurology and ophthalmology

• Evaluates and manages vision problems caused by brain or nerve conditions (e.g., stroke, MS, tumors)

• Assesses visual field loss and eye movement disorders

Optometrist

• Doctor of Optometry (OD) focused on vision care and eye health

• Performs eye exams, prescribes corrective lenses

• Screens for eye diseases and refers to ophthalmologists for advanced care

Behavioral Optometrist (Vision Therapy)

• Optometrist with a focus on how vision impacts behavior, learning, and function

• Provides vision therapy to improve tracking, focus, eye coordination, and visual processing

• Often works with children or clients with brain injuries

Physiatrist

• Medical doctor (MD) specializing in physical medicine and rehabilitation (PM&R)

• Manages rehabilitation for clients with neurological or musculoskeletal issues

• Coordinates care with OT, PT, and SLP; may oversee recovery after stroke or TBI involving vision impairments

Anatomy

Anatomical Feature	Function

Lens	Focuses light rays onto the retina

Cornea

Transparent front layer; allows light to enter the eye

Pupil

Regulates how much light enters the eye by dilating or constricting

Iris	Colored part of the eye; controls pupil size

Vitreous Body

Gel-like substance between lens and retina; maintains eye shape and helps transmit light

Optic Nerve

Transmits visual information from the retina to the brain’s visual cortex

More anatomy of the eye

 

ANATOMICAL FEATURE OF THE EYEBALL	FUNCTION
Fovea	Located in the retina, provides the most acute vision
Macula	Located near the middle of the retina. Enables visualization of objects with great detail
Retina	Sensory membrane that lines the eye. Receives images from the lens and converts them into signals that reach the brain via the optic nerve
Choroid	Layer of blood vessel; provides nourishment to the back of the eye
Sclera	White portion of the eye

Visual Acuity and Fields

• Acuity

  • Sharpness of vision

• Visual field

  • Extent of visual space that is visible

    • 65^o upward

    • 75^o downward

    • 95^o outward

    • Functionally 180^o horizontally & 125^o vertically

• Visual field deficits

  • Blind spots in a portion of the visual field

Types of Loss

 

Type	Description
Hemianopsia	Vision loss in one half of the visual field in one eye
Homonymous hemianopsia	Vision loss in one half of the visual field on the same side of both eyes
Quadrantopsia	Vision loss in one quarter of the visual field

Visual Skill Terms

Term	Definition
Oculomotor Control	Ability to move the eyes smoothly and accurately in all directions
Convergence	Eyes moving inward together to focus on a near object
Saccades	Rapid eye movements that shift focus from one object to another
Fixation	Ability to maintain steady gaze on a single object

Diplopia (Double Vision) Clinical Observations:

• Client may close one eye to avoid seeing double

• Complaints of blurred or double images

• Difficulty with reading, walking, or ADLs

• Head tilt or abnormal posture to compensate

OT Interventions:

• Occlusion techniques: Temporary eye patching (alternating or partial occlusion, under physician guidance)

• Environmental adaptation: Reduce clutter, improve lighting

• Prism training (with supervision): Reinforce awareness and compensatory scanning

• Functional tasks: Practice ADLs with visual cueing and guided head movement

Physician Interventions:

• Referral to neuro-ophthalmologist or optometrist

• Prism glasses prescription

• Botox injections (for muscle imbalance)

• Surgical correction if persistent and impairing function

Pattern Recognitiona and Visual Memory

Pattern Recognition Definition:

The ability to identify features of an object (shape, color, texture) and distinguish it from others.

OT Interventions:

• Matching games: Match shapes, colors, objects, or pictures

• Sorting tasks: Categorize items by size, shape, or function

• Puzzles: Simple to complex jigsaw puzzles to reinforce visual-spatial awareness

• Functional tasks: Sort laundry, organize kitchen tools, or match socks

• Spot the difference: Identify changes or missing items in images

Visual Memory Definition:

The ability to recall and recognize visual information after a brief delay.

OT Interventions:

• Memory matching cards: Turn over and match images from memory

• Copy then recall: Have the client copy a shape or word, remove it, and reproduce it from memory

• Repetition drills: Repeated practice with recalling faces, names, signs, or object placements

• "What's missing?" tasks: Show an image, remove one element, and ask what’s missing

• Functional applications: Remember steps in grooming, location of kitchen items, or visual details in a daily schedule

Visual Perception Definition:

“The dynamic process of receiving the environment through sensory impulses and translating those impulses into meaning based on previously developed understanding of that environment.”

Key Points:

• It’s not just seeing, but interpreting what is seen

• Involves recognition, interpretation, and response to visual stimuli

• Relies on past experiences and learning to give meaning to what is seen

• Essential for performing functional tasks like reading, dressing, navigating, and organizing objects

Examples in OT:

• Identifying objects during grooming

• Reading and writing

• Locating clothing in a drawer

• Safely navigating a room

Visual Discrimination

Spatial Relations

Definition: Understanding where an object is in relation to self or other objects
Example OT Activities:

• Positioning a toothbrush in the holder

• Placing dishes into a drying rack correctly

• Navigating around furniture during mobility tasks

Form Discrimination

Definition: Recognizing and distinguishing the important features of different objects (e.g., size, shape, texture)
Example OT Activities:

• Identifying coins or buttons by feel or sight

• Sorting silverware or puzzle pieces

• Matching clothing by fit and form (e.g., left shoe vs. right shoe)

Figure Ground

Definition: Differentiating an object from the background or surrounding objects
Example OT Activities:

• Finding a pen on a cluttered desk

• Locating a sock in a patterned laundry pile

• Reading text on a busy or decorative background

Visual Closure and Depth Perception

Visual Closure

Definition: The ability to recognize a complete object or image when only parts are visible
Example OT Activities:

• Completing partially drawn pictures or puzzles

• Identifying a familiar item when part of it is hidden (e.g., a shoe sticking out under a bed)

• Recognizing letters or words when parts are obscured (e.g., smudged handwriting)

Depth Perception

Definition: The ability to judge how far away an object is or perceive the space between objects
Example OT Activities:

• Pouring liquids without spilling

• Reaching accurately for a cup or utensil on a table

• Navigating stairs or curbs safely during mobility

Hemi Deficits

Hemi-Inattention

Definition: Decreased awareness of one side of the body or environment (commonly the left side after right brain injury)

Hemi-Neglect (Unilateral Neglect)

Definition: More severe form of hemi-inattention; the person has no awareness of the affected side and may act as if it doesn’t exist

OT Interventions

• Visual scanning training: Teach the client to actively turn head and eyes toward the neglected side

• Lighthouse strategy: Guide client to scan left to right repeatedly, like a lighthouse beam

• Tactile & verbal cues: Use touch or voice prompts to bring attention to the neglected side

• Mirror therapy: Use mirrors during ADLs to increase visual awareness of affected side

• Functional tasks: Encourage bilateral tasks (e.g., folding towels, washing face) that require use of both sides

• Weight-bearing: Incorporate weightbearing or movement through the neglected side (e.g., leaning on left arm during tasks)

Agnosia

• Agnosia – inability to recognize/perceive sensory info

• Prosopagnosia – inability to recognize faces

• Simultagnosia – inability to perceive entire picture or integrate its parts

• Tactile agnosia (astereognosis) – inability to recognize objects by feel

• Auditory agnosia – inability to recognize sounds

• Object agnosia – inability to recognize objects 

• Intervention is generally a compensatory strategy

Vision Conditions

Condition	Main Problem	Vision Loss Pattern	Cause	Key Feature

Macular Degeneration (most common)

Damage to the macula (central retina)

Loss of central vision

Age-related degeneration

Can’t see fine detail; peripheral vision intact

Cataracts

Clouding of the lens

Blurry or cloudy vision (global)

Aging, trauma, or medical conditions

Glare sensitivity; colors appear faded

Glaucoma

Damage to optic nerve from high eye pressure

Loss of peripheral vision (tunnel vision)

Increased intraocular pressure

Often painless and progressive

Diabetic Retinopathy

Damage to retina’s blood vessels

Patchy vision loss, floaters, blind spots

Uncontrolled diabetes

May lead to total blindness if untreated

Hemianopsia

Brain damage (usually stroke-related)

Loss of half the visual field (left or right)

CVA or brain injury

Not an eye problem — it's a visual field cut

Low Vision

Someone with low vision can often complete basic ADLs (like dressing, eating, and personal hygiene) because these tasks don't typically require detailed visual input or can be adapted with touch or other senses. However, they may struggle with work, leisure, and many IADLs due to the higher visual demands:

• Driving: Requires clear and precise vision for safety, navigating, and reading signs.

• Pet care: Involves visual monitoring of the pet’s health, activities, and behavior, which can be challenging without good vision.

• Financial management: Tasks like reading bills, counting money, and using a computer or phone for transactions rely heavily on visual accuracy.

• Home management: Activities like cooking, cleaning, or organizing often require the ability to visually locate and identify objects, check expiration dates, or assess cleanliness.

Aids for Low Vision

compensation, adaptations, equipment, and environmental modifications. Here's how OT can help:

1. Education: Teaching clients strategies to maximize their remaining vision and use other senses to complete tasks.

2. Environmental Adaptations: Modifying home or work environments to improve safety and function. For example:

   • Lighting: Increasing light intensity or using task-specific lighting to enhance visibility.

   • Color Contrast: Using contrasting colors on objects (e.g., white labels on dark containers) to make them easier to see.

3. Tactile Cues: Adding raised symbols or textures to help with locating objects (e.g., textured labels or knobs).

4. Aids and Equipment:

   • Magnifiers: Hand-held or stand magnifiers to enlarge text or images for easier reading.

   • Writing Aids: Large-print pens, paper guides, or electronic devices that convert text to speech.

   • Kitchen Aids: Adaptive tools like talking kitchen scales, large-print measuring spoons, or tactile timers to help with cooking and meal preparation.

Reading with Low Vision

• Matte Paper: Reduces glare and makes text or images easier to read by using non-reflective surfaces.

• Finger Guiding: A technique where the person uses their finger to follow along text or objects, helping to maintain focus and reduce misreading.

• Anchor Lines: Horizontal or vertical lines used to help orient the person when reading or writing, assisting with alignment and preventing skipping of lines.

• Good Lighting: Proper illumination is essential for maximizing any remaining vision. Using bright, focused lighting helps reduce eye strain and increases contrast.

• Contrast: Using high contrast between background and text (e.g., black on white, yellow on black) helps improve readability for individuals with reduced vision.

• Larger Font: Increasing the size of text, whether in print or on screens, makes reading easier for individuals with central or peripheral vision impairments.

Adaptations

• Read at a table away from a window: Positioning oneself away from a window helps avoid glare and shadows that can make it difficult to see text or objects clearly.

• Read on a wooden table instead of glass: Wooden tables are less reflective than glass, reducing glare and making it easier to focus on reading materials.

• Enlarge the font on the computer or phone screen: Increasing the font size on digital devices makes text easier to read and reduces the strain on remaining vision.

• Put a paperclip on the left-hand page: This creates a tactile cue, helping the individual orient the page and maintain their place while reading, which is especially helpful for individuals with central vision impairments.

More adaptations

• Put different colored stickers on medication bottles: Using color-coded stickers helps differentiate between medications, making it easier to identify each bottle, especially when fine details may be hard to read.

• Put a colored transparent sheet over the paper: A transparent colored sheet can enhance contrast, making text stand out more clearly against the background, which is helpful for individuals with certain types of vision impairments.

• Read books on an e-reader or tablet: E-readers and tablets allow for easy font size adjustments, contrast changes, and background color modifications, providing a customizable reading experience for individuals with low vision.

• Turn the head to one side while reading: For individuals with peripheral vision loss, turning the head to one side can help them use the more functional area of their visual field, improving their ability to see text or objects more clearly.