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Vision and DrivingSeeing Your Way to Better Client Outcomes

Beth Rolland, OTR, CDRS

What is Vision

The primary sense that we use to acquire information about our environment.

IncludesEye movementAcuityPerception

Vision Facts

90% of the information we gather comes from the visual system.

Vision allows us to be anticipatoryThe visual system is the fastest and

most complicated of all sensory systems.

50% of all neurologic insults cause visual deficits.

Vision Facts

Eye is the only organ in the body innervated by both the central and autonomic nervous systemsCentral – voluntary movements

(pursuits, saccades, lid opening/closing)Autonomic – involuntary control (pupil

constriction and dilation)

Vision Facts

The visual system provides the highest level of sensory information processing in the human body and is the most highly integrated of all systems.

It is estimated that 65% of all nerve fiber interactions with the brain have something to do with the visual information processing system.

Anatomy of the EyeAn Overview

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Anatomy of the EyeEye Structure & Function

Eye parts resemble a camera Sclera - white outer protective coat; the

"white of the eye". Cornea - transparent, curved structure in

front Iris - colored part seen through the cornea. Pupil - black part in the middle of the iris.

Constricts or dilates according to the amount of light passing through.

Lens - transparent disc (with both sides being convex) immediately behind the iris and pupil.

Eye Structure & Function

Aqueous humour - transparent fluid (water consistency) circulates behind cornea and in front of the lens.

Vitreous humour – fills the eyeball between lens and retina (like transparent jelly).

Retina - light-sensitive layer of millions of nerve cells lining back of the eyeball. Rod cells – tall, thinCone cells - rounder


Rods - more numerous, mostly at outer edgerespond to low levels of light, peripheral

movement. Cones - far fewer, concentrated in center

respond to color and details. Macula - small center of the retina

responsible for central vision—ie: reading. Retinal pigment epithelium – dark layer of cells at

back of retina Provide oxygen & nutrients to rods/cones.


Choroid - large network of blood vessels (behind the retina) transport oxygen & nutrients to retinal pigment

cells. Optic disc - small yellow oval structure in retina

nerve cell connections travel from all the rods and cones.

Optic nerve and beyond - "cord" of nerve cell connections that passes from eyeball to destinations throughout brain.


Retina –located at the back of the eye and connected

to the brain. made up of many millions of light-sensitive cells

known as photoreceptor cells which transmit electrical impulses to the brain to enable sight.

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Cranial Nerves

Cranial Nerve II (Optic Nerve)Originates at the RetinaConnected to the specialized receptors

in the retina—the rods and cones.Exits the back of the eye in the orbitWhere the optic nerve tract begins.

Cranial Nerve II (cont.)

The optic nerve has only a special sensory component

Visual information enters the eye in the form of photons of light

Light is converted to electrical signals in the photoreceptors (rods and cones) located in the retina

Signals travel optic nerves, chiasm, and tract lateral geniculate nucleus (thalamus) occipital lobe (visual centers)

Cranial Nerves

Cranial Nerve III (Oculamotor Nerve)Raises eyelid and controls pupils

Drooping eyelid = ptosis

Controls several key eye muscles. These muscles include the following: Superior Rectus: the ocular muscle whose contraction turns

the eyeball upward and medially Inferior Rectus: the ocular muscle whose contraction turns

the eyeball down and medially

Cranial Nerve III (cont.)

Medial Rectus: the ocular muscle whose contraction turns the eyeball medially

These muscles are an integral part of how well and how smoothly your eyes move.

Cranial Nerves

Cranial Nerve IV (Trochlear Nerve) Purely motor nerve supplying one muscle: Superior oblique: Intorsion-

inward rotation of upper part of eye about an axis or a fixed point. Secondary movement-moves

eye out and down.Damage results in eye slightly

elevated in primary gaze position (straight ahead gaze)

Cranial Nerves

Cranial Nerve VI (Abducens Nerve)Lateral Rectus:

Pulls the eye away from the nose

Damage to this nerve will result in the affected eye turning inward (cross eye)Intermittent double vision in lateral gazeEffect of esotropia is greater at distanceReading ok, driving a problem

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Cranial Nerve Summary

Nerve Nerve supplies Function Clinical observations

CNIII- oculomotor Upper eyelidSR, IR, MR, IOCiliary MuscleSphincter of Iris

Eyelid movementEyeball movement-up,down, and mediallyPupil constriction

PtosisExotropia (down&out)Diplopia at nearNo pupil accomodation

CNIV-trochlear Superior obique Eyeball movement- downand out

Hypertropia/phoriaVertical diplopiaLateral tilt of head

CNVI- abducens Lateral rectus Eyeball movementoutwards

Esotropia/phoriaDiplopia at distance

Eye Anatomy Videos

Dr. Tim Roothttps://timroot.com/anatomy-of-the-eye-

video/Anatomy videoNeuro-anatomy Functional Vision

Hierarchy of Visual Adaptation

Oculamotor Control (pursuits, saccades)

Visual AttentionVisual ScanningPattern RecognitionVisual MemoryVisuo-Cognition (perception)Adaptation (thought, reasoning)

Oculamotor Control

Visual Fixation - ability to find target and hold eyes on it

Pursuits – ability to follow a moving target (without head movement)

Saccades – rapid eye movements in any direction (without head movement)

Implication for driving: if you can’t see it, you can’t respond to it!; objects are moving in driving environment – pedestrians, bicycles, cars

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Visual AttentionCognitive componentAbility to pick out relevant information in an

environment and suppress irrelevant informationSustained attention – maintain over timeShifting attention – change focus from one thing to

another rapidlyDivided attention – attend to multiple factors at

once (ie: hazards on both right and left side)

Implication for driving: if you are not paying attention, you will miss things

Visual Scanning

Visual Scanning – ability to find things in the environment

Peripheral Vision – what can be seen on the side without head or eye movementNot clear, but brain fills in and seems clear Alerts to movement – prompts saccade or head

turn to use central vision for more information

Implication for driving: hazards come from all fields; inadequate scan will miss things

Visual Fields – Peripheral Vision

Norms: 65 degrees upward

70 degrees downward

60 degrees nasally

90-110 degrees temporally

Pattern Recognition

Cognitive process that matches information from a stimulus with information retrieved from memory Allows anticipatory awareness

Implication for driving: if you don’t anticipate, you will respond late

Visual Memory

Recollected information about what one has seen. Mental storage of informationAbility to retrieve stored information

Implication for driving: deficit may lead to difficulty finding your way, finding your car in a lot, remembering what was on the left when you scan right

Visuo-Cognition (perception)

Ability to process and interpret meaning from visual information gained through eye sight visual discrimination visual figure ground – distinguishing object from background visual closure – “seeing” the whole from a part visual memory – recalling what you saw visual form constancy – recognizing objects when they are

turned around visual spatial relationships – where one thing is in relation to

another visual-motor integration – eye/hand coordination

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Visual Perception

Implication for driving: Poor lane position

Unsure where they are relative to parked cars, lanes Unable to coordinate steering movements quickly enough

to maintain straight path Improperly placed turns

Unsure where to start turn – especially lefts Unsure where curve starts for rights

Poor sign recognition (ie: branch over stop sign) Difficulty driving at night (poor contrast)

Other Crucial Vision Skills

Visual Acuity

Ability to focus either near or farExpressed as a fraction

Numerator: testing distance at which stimulus is recognized

Denominator: distance at which letter being viewed could be recognized by a person with normal visual acuity (20/20)

Implication for driving: state laws for minimum; inability to read signs or see road details

Visual Acuity

Includes Contrast Sensitivity Ability to see objects of decreasing contrast rather than size

High contrast: black on white, etc. Low Contrast: grey on white; white on white, etc.

Contrast Sensitivity has been linked to crash risk

Implication for driving: difficulty driving at night, dusk or dawn; difficulty seeing items against same color background (green car with green bushes)

Contrast Sensitivity Binocular Vision

Combining images from each eye into single image. Images must fall precisely on corresponding positions on

each retina or double vision will occur. Muscles work together to position eyes properly to focus

light on center of each eye, providing clear vision.

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Binocular and Stereoscopic Vision

Binocular Vision

Focusing near - eyes move closer together (convergence)

Focusing far - the eyes move further apart (divergence)

Misalignment of eyes – double vision Double vision usually either near OR farMuscle weakness pulls eye opposite

May be in one gaze (ie: far left gaze) May be constant

Implication for driving: blurry vision, motion sickness, inability to accurately judge space

Stereoscopic Vision

Depth Perception Slight difference in angles of images received in each eye gives

images depth Loss or suppression of one eye affects depth

Do use other cuesLight, shade, shadows, color and relative

sizes of objects contribute to depth Cognitive component - learn the signs

that enable them to perceive depth.

Implication for driving: difficulty judging space and speed

Binocular and Stereoscopic Vision

People think and learn best in three dimensions. When scanning text quickly, we can absorb 100

letters per second - the computer equivalent of 100 bits per second.

When glancing at a three-dimensional object, we can see the equivalent of 1 billion bits per second.

Implication for driving: good binocular vision lets you see faster and react faster on the road

Vision Screen

Visual History

Patient complaints (diplopia, blurred vision, dizziness, headaches, eye fatigue, balance difficulties)

Optical History (cataracts, glaucoma, diabetes, macular degeneration, surgery)

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Evaluating Far Acuity

*Must pass state standard for vision in state they hold license

Options:Optec Vision Tester – quick and easy; also

tests contrast sensitivity, alignment, depth, color, road sign recognition

Snellen or Lea Chart – cheap and easy


Test each eye separately and then together (Optec tests separately with both eyes working)Many states have requirements that

both eyes pass the standardTesting separately lets you know which

eye has an issue

Visual Acuity

Equipment Select appropriate assessment tool (Optec,

Snellen chart/ Lea symbols)


Optec ProcedureClient wears corrective lenses for distanceBegin at 20/40 line

Left eye sees left column; right eye sees right column; both eyes see middle column

If client does not start with left column, turn off right eye and have them try again

If client does not read right column, turn off left eye


OptecInstruct client to read down to last line

they can make outFar acuity is last line where 3 out of 4

letters in the column are identified correctly

If the client has aphasia, try giving them a piece of paper and pencil to write the letters


Snellen Chart (or Lea Chart) ProcedureStand 10 or 20 feet away (based on chart)Client wears corrective lenses for distanceTest monocularly then binocularlyBegin at 20/40 line (or line required by state of

license)If patient has difficulty, isolate lines

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Snellen ChartUse Lea symbols if client has aphasiaFar acuity is last line where 75% or

more of letters are identified correctly


A large discrepancy between eyes can lead to suppression and will affect depth Two line discrepancy – refer to a vision specialist

Older patients often have cataracts, which affect acuity May not meet state standard for vision


Some folks have trouble with Optec If not meeting standard in Optec, try Snellen

**In most cases, it is not legal to take a client on the road if vision does not meet state minimum If below state standard, refer to eye doctor May have to wait for cataract surgery prior to BTW

Evaluating Contrast Sensitivity

Optec 5000 – contrast slidesDay and night testingCan also test glare

Contrast Sensitivity Chart

Contrast Sensitivity-Optec Contrast Sensitivity Charts

Pelli Robson Chart

Hamilton-Veale Chart

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Evaluating Pursuits

Equipment – colored target, eye patchProcedure:

Patch one eyeTest without glassesHave client hold head still and follow target as

you move it. Hold target 16” from patient and move in the

form of “H”, “X” and “O”

Evaluating Pursuits

Look for: choppy movement, inability to move the eye through entire range of motion, nystagmus (slow beating motion), excessive head movement

Refer to eye doctor if deficits are significant Nystagmus – often in extreme side gaze; can be in

primary gazeWill blur image on that side Can appear like double vision Client will have to be taught to turn head to that side

rather than relying only on saccades

Evaluating Saccades

Equipment: two different colored targets; eye patch

Procedure:Patch one eyeTest without glassesHave patient hold head still and look back and

forth between the targets on your commandHold targets 16” from patient, 12” apartTest in upward, horizontal and downward gaze

Evaluating Saccades

Look for: choppy movement, overshooting, undershooting, nystagmus, searching for target, inability to disassociate head and eye movementsSearching for target may mean field cut or

inattention on that sideMay benefit from visual exercise programRefer to eye doctor with overshooting,

undershooting, significant deficit, searching for target on return (suspect neglect)

Evaluating Visual Fields

Optec has visual field test Will only test horizontal field

Will not test superior or inferior field cutsIf you suspect a field cut, don’t rely only on Optec

Easy for client to cheat!They will move eyes to search for targets

Clients don’t always understand directionsMix up right, left and both


Double simultaneous stimuli Will detect field cuts in planes other

than horizontalObvious when cheating!Use with known or suspected field cutUse with clients who have difficulty

with Optec

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Optec procedure:Test without glasses (ear piece often obscures

target)Instruct client to look straight ahead

Emphasize that targets will not be in the picture, but will be well to the side

Randomly choose targets right, left or both Check each target several times

Look for targets missed repeatedly, targets seen when singular but missed when double (suspect inattention/neglect), delay in responding


Double simultaneous stimuli procedure:Patch one eye, sit opposite client and instruct

them to look at your nose at all timesStart with arms in horizontal plane and

determine end ranges of fieldsInstruct client to identify right left or both

fingers moving Start with single stimulus then move to

simultaneous stimulus Repeat procedure for vertical and diagonal

planesRepeat binocular (inattention more obvious)


Norms: 60-65 degrees upward

70-75 degrees downward

60 degrees nasally

90-100 degrees temporally

Clinical Correlations1.Macula

2.Optic Nerve

3.Optic Chiasm

4.Optic Tract

5. Lateral Geniculate

6.Optic Radiation

7. Visual Association

8. Primary Visual Area

Visual Field Loss

Homonymous field loss – both eyesHemianopsia – half of field; severe loss

Many states will not allow driving with HHQuadranopsia – one quarter of field

Temporal lobe – usually upper fieldParietal love – usually lower fieldEasier to compensate for upper field loss

Location of infarct will dictate field loss Infarcts further back will cause greater loss and be more

permanent More likely to be in one eye if further forward

Visual Field Loss

• Right Homonomous Hemianopsia

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Visual Field Loss

• Binasal Hemianopsia

Visual Field Loss

• Bitemporal Hemianopsia

Visual Field Loss

• Quadrantopsia

Visual Field Inattention/Neglect

Can be with field loss or withoutThree types (may have one or all)

Personal space – dressing, shaving, washing facePeripersonal space – arm’s reach, desk activities

Will show up with cancellation tests, field testing, clock drawing, Rey Osterreith figure copy

Extrapersonal space – beyond arm’s reachDifficult to test in officeMore dangerous for drivingMay veer to one side when walking; miss doorway to

office,

Evaluating Inattention/Neglect

Look for patterns: Poor saccade to one side (searching on return) Difficulty with field testing (maybe just unpredictable)Odd clock drawing Leaving out details on one side of Rey Osterreith copy Taking longer to find targets on one side of Trails A or B Ignoring small peripheral shapes on Visual Form

Discrimination Test

Evaluating Inattention/Neglect

Clock drawing Ask client to draw a clock with all the numbers on it, and

the time reading “10 minutes past 11” Look for:

spacing – even, or more on one side? (inattention)

Hand placement (abstract skills)

Rey Osterreith copy Have client copy the picture Look for missing details on one side

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Clock Drawing Test Rey Osterreith Figure Copy

Rey Osterrieth Errors Evaluating Convergence

ProcedureClient wears reading glasses if applicableHold a pencil 16” in front of client’s noseSlowly move pencil toward client’s noseClient tells you when pencil doublesOR – note when one eye stops coming in toward

the noseNormal is 2”-4” from nose

Evaluating Alignment

Optec – simple, quick Use slide with musical notes and arrow Ask client if they see both notes and an arrow

pointing down from the top of the slide Have them identify to which number note the

arrow is pointing Normal range – between 4 and 12


Corneal Reflex ProcedureHold pen light 16” from bridge of noseClient looks at lightObserve reflection in both pupilsLook for symmetry of reflection

Medial reflection indicates exophoria

Lateral reflection indicates esophoria

**Do not perform if seizure precautions!**

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Maddox Rod Procedure Test each eye separatelyHold rod so lines on rod are oriented horizontallyStand 10 feet from clientHold penlight behind card and direct light through

the hole in the center Client indicates which number the vertical line

passes through. This represents horizontal alignment

Repeat with lines on rod oriented vertically for vertical alignment

**Inability to see line may be a suppression**

Evaluating Visual Scanning

Paper & Pencil Scan sheets C & E Cancellation Sheet Trails A Mesclun Scans Star Cancellations Disadvantage: small space – mostly focal vision

Evaluating Visual Scanning

Dynavision or Wayne Sacadic Fixator Advantage: bigger space; uses periphery Disadvantage: cost, size If your clinic has one, great test to add

Norms Grossly looking for one target per second (60

targets/minute)

Dynavision

What do I do if I find a vision deficit??

Neuro-optometrists

Specialize in functional visionEvaluate more than acuity and eye healthUse interventions such as prism lensesRefer clients for therapy (or treat in their

offices)

Find one and get to know them!Source of referrals as well as help for

your clients

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Neuro-optometrists

NORANeuro-optometric Rehab Assoc.https://nora.cc

Search feature to find a provider

Courses in evaluation and treating vision dysfunction

Neuro-optometrists

Put off Behind the Wheel evaluation if deficits are significant and have not been addressed Both neurological and congenital diagnoses

may make it to you before a good functional evaluation

If training in the car and noticing poor tracking, trouble with curves/turns, take a step back and send for vision therapy

Vision Therapy

OT clinic with a vision rehab programNeurological Outpatient Rehab siteOften covered by insurance

Neuro-optometrist with in-office programOften out of pocket expense

Vision Exercise Program

Deficits in Pursuits/Saccades Thumb Rotations - pursuitsHart Charts - saccadesEyecanlearn.com

Tracking – Pursuits/SaccadesProgram for kids, but good for adults also

Brock String – eye pointing, accomodation

Vision Deficits Common in Older Drivers

Skills that Decline as we AgeAcuityContrast sensitivitySpatial skillsPeripheral fieldsAwareness – particularly of the periphery,

and of multiple targetsVisual processing speed Anticipatory decision makingVisual/Physical reaction – “reflexes”

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Vision Deficits

Visual Acuity Static – ability to focus on a target

State standards differ

Road signs designed for 20/40

NJ does not retest after initial licensing (!)

Dynamic – distinguishing details of objects in motion

Useful field of viewVisual area over which information can be

extracted at a brief glance without eye or head movements.

Correlated to crash risk in older drivers UFOV decreases with age

decreases in visual processing speedreduced attentional resources less ability to ignore distracting information.

40% of 90 year olds have a UFOV of less than 20 degrees (tunnel vision)

Visual Diseases/Disorders

Macular DegenerationLoss of central vision; periphery intactVery dangerous for driving as it worsens

ScotomaLoss of a spot of vision (macular degeneration, optic

neuritis, surgery, etc.)Can sometimes learn to move head and adjust spot

to a place it does not interfereGlaucoma

Increased fluid pressure-damages optic nerveLoss of peripheral visionPoor night vision

Visual Diseases/Disorders (cont.)

CataractsClouding of the lens--loss of acuity/hazy visionPoor night vision

Diabetic RetinopathyLeakage and other damage to blood vessels of

the retinaRetinal scars; blind spots from laser treatments

Visual Diseases/Disorders (cont.)

Low Vision Significantly decreased acuity

Bioptic Lenses—some states allow Require significant training

Outside the car

Inside the car

Macular Degeneration

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Scotoma 20/200 Acuity

Glaucoma

Vision Deficits Common after Stroke/TBI

Ocular-motor deficits

Pursuits, saccadesCranial nerve damage

III drooping eyelid; may impair peripheral vision Eye postures down and out

IV – Difficulty with downgaze Head tilt to opposite side

VI eye won’t move out (“cross eye”) **big effect on driving

Decreased ability to scan for hazardsNystagmus—abnormal oscillations of eye(s)

Cranial Nerve III Damage

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Cranial Nerve VI Damage Poor Alignment

Strabismus (tropia) – unable to voluntarily align eyes to look at an object; constant “Cross Eyed” – one eye deviates medially “Wall Eyed” – one eye deviates laterally Corrected surgically

Phoria – misalignment that fluctuates; more apparent with fatigue May be alternating – either eye different times

Alignment Deficits

SuppressionBrain ignores image from one eyeCommon when there is double visionLoss of depth perception

New? Or longstanding?

Fusion deficitsNot using both eyes together as a team

Loss of depth perceptionNew? Or longstanding?

Visual Field Loss

Homonymous field loss – both eyesHemianopsia – half of field; severe loss

Many states will not allow driving with HHQuadranopsia – one quarter of field

Temporal lobe – usually upper fieldParietal love – usually lower fieldEasier to compensate for upper field loss

Location of infarct will dictate field loss Infarcts further back will cause greater loss and be more

permanent More likely to be in one eye if further forward

Visual Field Loss

• Right Homonomous Hemianopsia

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Visual Field Loss

• Binasal Hemianopsia

Visual Field Loss

• Bitemporal Hemianopsia

Visual Field Loss

• Quadrantopsia

Vision Deficits (cont.) Peripheral Deficits

Visual Field Cuts One eye only – easier to compensateHomonymous – most states won’t allow driving (NJ & NY

do, PA does not)Normal binocular field=180 deg. side to side

Effect of vehicle speed on Visual Field200 deg field at 20 mph=104 degrees200 deg field at 40 mph=70 degreesNormal VF at 60 mph=40 degreesField deficit will worsen as speed increases

Peripheral vision is not clear—alerts to motion

Visual Attention Deficits

Inattention/Neglect (neurological dx) Field is either normal or decreased

Unfit for driving if extrapersonal—needs to resolve first

Unable to compensate

Decreased divided attention Field can be either normal or decreased

Work in clinic first

Common in neurological dx, but also prevalent in the well elderly

Impaired Visual Processing

Combines visual and cognitive systemsSlow Processing common in:

Neurological dx – CVA, PD, MS, TBIGeneral aging population

Compounded by: Low illuminationStressIllnessFatigueSensory overload

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Spatial Skills Deficits

Figure Ground Differentiating foreground from background

Form Constancy Attending to subtle variations in form

Perceiving the whole object when you only see a piece of it

Position in Space Up/down, front/behind, left/right

Spatial Skills Deficits (cont.)

Topographical Disorientation Relationships of places to one another

Finding your way in space

Spatial Relations Position of objects in relation to each other

Interpreting speeds of movement

Spatial Skills Deficits (cont.)

Implications for DrivingTime and space management (stopping too late

or too soon at intersections)Parking difficulties (esp. backing)Not seeing signs, confusing arrowsInterpretation of the unexpected

(construction, car breakdowns)Maneuvering difficulties—position on roadGetting lost in familiar surroundingsLane selection

Vision Deficits Common with Congenital Diagnoses

Vision Deficits

Congenital Diagnoses that often present with vision deficitsCerebral PalsySpina BifidaLearning DisabilitiesADHD/Asperger’sRetinitis PigmentosaAlbinism

Cerebral Palsy

Common DeficitsStrabismus or Phoria Poor Binocular visionAbsent depth perceptionPoor visual/spatial skillsSlow scanningDifficulty multi-tasking

Often have difficulty with lane position, turns and curves

Often see detail at expense of big picture

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Spina Bifida

Common deficitsWeak eye muscles – strabismusPoor scanning skills

ADHD/Asperger’s

Common deficitsDifficulty with visual multi-taskingDifficulty disassociating head & eye movementsInefficient visual scanning – or looking for the

wrong things Often see detail at expense of big picture

Watch Rey Osterreith drawing

Retinitis Pigmentosa

Common deficitsUnable to see the color redVery poor contrast sensitivity (see brake lights

better in the dark)Low vision – often referred with bioptic lensesDecreased peripheral visionPoor night vision

Ocular Albinism

Common deficitsReduced pigment in eye – crucial for visionLow visionPoor depth perceptionNystagmusStrabismusPhotophobiaAbnormalities in optic nerve – affects

connection to the brain

Driving with Low Vision

Bioptic Lenses

For drivers whose acuity cannot be corrected to the state minimumCarrier lens plus telescopic lensDriver uses carrier lens 95% of timeUses telescopic lens to read signsLegal in 37 states, including NY, NJ, PA

Requires significant training OUTSIDE the car prior to any driving

Requires a driving specialist with special training

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Driving with Vision Deficits

Driving with Homonymous Hemianopia (HH)

Homonymous hemianopias (HH) Approx. 40% of post-chiasmal lesions

22 states and many countries do not allow driving (2009) Disqualified by arc of vision requirement

Some allow after special evaluation

Monocular Sector Prisms Can increase arc of vision enough to qualify

No research yet to determine if they increase safety (Elgin) Recommend training prior to evaluation on-road

Driving with HH

HH ResearchNo study has looked at actual crash rates Prognosis may be better with macular sparing Lower accuracy in seeing pedestrians in simulator and

traffic/pedestrians in on-road study (Bowers I)Widely differing abilities to compensate (miss rates

from 0-100% ) Greater incidence of positioning errors (over lane line

Bowers II) Age is the best predictor of blind-side miss rates

Driving with HH

HH research (cont.) Most detection errors occurred at intersections (Bowers pilot)

Scan magnitude was not large enough (especially to right side Bowers IV)

No peripheral vision cue how far to scan

Missing pedestrians, etc. on sidewalk

Judgment on fitness to drive cannot be based solely on visual field size (Gera)

Longer time not driving adversely affects outcome (Gera)

Better prognosis with good contrast sensitivity and faster processing speed (Elgin) Research shows that many people with HH are driving AMA

Evaluation – Field Cuts

Tips for Evaluators Know the law in your state for peripheral fields

Clients with significant field loss may be able to drive safely

Question client about navigation in crowded places – malls, supermarkets, etc. Do they run into things?

Send to an OT vision specialist to learn scanning strategies and improve speed and accuracy outside the car first less expensive (often covered by insurance)

safer

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Evaluation – Field Cuts

Tips for Evaluators Look closely at the following maneuvers during BTW:

lane position – middle line, shoulder line, lane choice

intersection hazard detection – are they scanning far enough to see the sidewalk on both sides?

steering stability – do they hold a straight line?

One drive is not enough to make decision Routes should include a variety of traffic scenarios

Choose routes that challenge client from the blind side

Choose areas with pedestrians

Insist on 8-10 drives with different traffic and times of day

Familiar roads will be safer – but there can be changes, detours, surprises

Training Techniques-Field Cuts

Teach compensation techniques Look as far down the road as possible Turn head when approaching targets identified

Children playing, cars at intersections, people getting into cars in driveways, bicycles, pedestrians

Keep eyes moving constantly Turn head and be especially vigilant at

intersectionsBe sure to scan far enough – all the way to sidewalk

to look for pedestrians


Teach compensation techniquesUse mirrors more frequently

Scan for aggressive drivers coming from behind, tailgaters, traffic in lane on vision loss side

Vigilently check the side mirror on side of lossBeware of parking lots!!

Uncontrolled air space – look for backup lights, pedestrians, doors opening, cars cutting across spaces, cars at ends of rows


Teach compensation techniquesChoose lane wisely

Driving in lane corresponding with field cut will eliminate cars cutting you off from that lane

Staying in the right lane will avoid difficulty of lane change to the left and vise versa – but eventually left lane drivers may have to lane change right to exit

Plan lane changes far in advance – don’t try to cut over at the last second


Teach compensation techniquesWith right side loss, beware of parking

lot entrances/exits, driveways, kids playing in yards

With left side loss, be wary of car in left lane directly next to you


Suggest technology If client can purchase a new vehicle, suggest the

following options: Blindspot detection Lane position detection Back-up camera – looking over shoulder will be harder

with field cut Intelligent cruise control

Address position of side mirrors to reduce blindspot

Suggest spot mirrors on both sides Suggest panel rearview mirror

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Training Techniques-Turns/curves/lane position

Teach client to look ahead, as far around the curve/turn as possibleLook for yellow line aheadTry to keep same distance from yellow line

Use landmarksThere is almost always a manhole where you

need to start a left turn

Use a magnet on the hood of the car to line up with the yellow line


Teach compensation techniquesWith right side loss, beware of parking

lot entrances/exits, driveways, kids playing in yards

With left side loss, be wary of car in left lane directly next to you

Training Techniques-New Drivers

Teach hierarchy of scanningMost important to least important (ie:

brake lights ahead vs. car in its lane approaching from ahead

Teach first as passenger – parent/you.Identify one thing, then two, etc.

Commentary driving

Training Techniques-New Drivers

Teach eyes up and outLook far down the roadUse saccadic eye movements

constantlyEmphasize hazardsBicycles, motorcycles, pedestrians,

runners, car approaching over center line

Techniques-Driving at Night

More difficult with: glaucoma, cataracts, photosensivity, poor contrast sensitivity

TechniquesDon’t look at headlights – look to

side of roadDrive new routes first in daylightUse yellow lenses to cut glare

Techniques-Driving in Bad Weather

More difficult with: glaucoma, cataracts, poor contrast sensitivity

TechniquesKeep windshield cleanWindshield wipers fully functioningSlow speedLeave greater following distance

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Techniques-Lane Position Difficulty

Teach client to use center (yellow line) as guideRight side of road expands and

contractsUse a magnet to line up with center

lineMay need vision therapyVisual midline off

Techniques-Vision/Vestibular Dysfunction

Common after ConcussionDizziness with head turnsUncomfortable with motion in the

peripheryMay feel movement that is not

thereDifficulty judging spaceConvergence and Accomodation

deficits

Techniques-Vision/Vestibular Dysfunction

StrategiesMove eyes first, then head to scanMove more slowlyExpanded rearview mirrors, spot

mirrorsVision therapy

Very effective for convergenceSlower roads, familiar routes at first

Vision Resources

NORA – www.nora.ccNeuro-optometric Rehab

Association – locate a neuro-optometrist

Bernell – www.bernell.comSource for vision testing and

training products

Questions References

Alberti CF, Peli E, Bowers AR. Driving with hemianopia: II. Detection of stationary and approaching pedestrians in a simulator. Invest Ophthalmol Vis Sci. 2013;55:369-374

Bowers AR, Ananyev E, Mandel AJ, Goldstein RB, Peli E. Driving with hemianopia: IV. Head Scanning and Detection at Intersections in a simulator. Invest Ophthalmol Vis Sci. 2014;55:1540-1548

Bowers AR, Mandel AJ, Goldstein RB, Peli E. Driving with hemianopia: III. Detection performance in a simulator. Invest Ophthalmol Vis Sci. 2009;50:5137-5147

Bowers AR, Mandel AJ, Goldstein RB, Peli E. Driving with hemianopia: I. Detection performance in a simulator. Invest Ophthalmol Vis Sci. 2009;50:5137-5147

Bowers AR, Tant M, Peli E. A pilot evaluation of on-road detection performance by drivers with hemianopia using oblique peripheral prisms. Stroke Res Treat. 2012; 2012:176806

de Haan GA, Melis-Dankers BJM, Brouwer WH, Bredwoud RA, Tucha O, Heutink, J. Car driving performance in hemianopia: in On-Road Driving Study. Assoc. for Research in Vision and Ophth. 2014:14-14042

26

References

Dickerson, AE. Screening and Assessment Tools for Determining Fitness to Drive: A Review of the Literature for the Pathways Project. Occupational Therapy in Healthcare. 2014; 28(2):82-121

Dickerson, AD, Bedard, M. Decision Tool for Clients with Medical Issues: A Framework for Identifying Driving Risk and Potential to Return to Driving. Occupational Therapy in Healthcare. 2014; 28(2):194-202

Elgin J, McGwin G, Wood J, Vaphiades MS, Braswell R, DeCarlo D, Kline L, Owsley C. Evaluation of on-road driving in people with hemianopia and quadrantanopia. Amer Journ of OT 2010; 64:268-278

Fisk GD, Owsley C, Mennemeier M. Vision, attention and self-reported driving behaviors in community-dwelling stroke survivors. Arch Phys Med Rehabil. 2002; 83(4):469-477

Fist GD, Owsley C, Pulley LV. Driving after stroke: driving exposure, advice and evaluations. Arch Phys Med Rehabil. 1997;78(12):1338-1345

Glass TA, de Leon CM, Marottoli RA, Berkman LF. Population based study of social and productive activities as predictors of survival among elderly Americans. BMJ 1999;319:478-83

References Glass TA, de Leon CM, Marottoli RA, Berkman LF. Population based study of

social and productive activities as predictors of survival among elderly Americans. BMJ 1999;319:478-83

Korner-Bitensky NA, Mazer BL, Sofer S, Gelina I, Meyer MB, Morrison C, et al. Visual testing for readiness to drive after stroke: A multicenter study. Amer Jour of Physical Med & Rehab 2000;79:254-259

Legh-Smith J, Wade DR, Hewer RL. Driving after a stroke. J R Soc Med 1986; 79:200-3

Liddle J, McKenna K. Older drivers and driving cessation. Br J Occup Ther 2003; 66:125-32

Lundquist A, Gerdle B, Ronnberg J. Neuropsychological aspects of driving after a stroke – the simulator and on the road. Applied Cog Psych, 2000;14, 135-150

Marrottoli RA, de Leon CF, Glass TA, Williams CS, Cooney LM, Berkman LF. Consequences of driving cessation: decreased out-of-home activity levels. J Gerontol B Psychol Sci Soc Sci 2000; 55:S334-40

Mazer Bl, Korner-Bitensky NA, & Sofer S. Predicting ability to drive after stroke. Archives of Phys. Med and Rehab. 1998;79:743-750

References

Michon, J.A. Explanatory pitfalls and rule-based driver models. Accident Analysis and Prevention 21. 1989, 341-353.

Michon, JA. A critical view of driver behavior models: What do we know, what should we do? L Evans & RC Schwing (Eds.) Human behavior and traffic safety, (pp. 485-520). New York: Plenum Press

Moss AM, Harrison AR, Lee MS. Patients with homonymous hemianopia become visually qualified to drive using novel monocular sector prisms. J Neuro-Ophthalmol 2014; 34:53-56 Owsley C, Ball K, McGwin G, et al. Visual processing impairment and risk of motor vehicle crash among older adults. JAMA 1998;279:1083-8

Pierce S, Blackburn, C. Building Blocks for Developing a Driving Program. 1999; p. 50

Schanke AK, Sundet K. Comprehensive driving assessment: Neuropsychological testing and on-road evaluation of brain injured patients. Scandinavian Jour of Psych. 2000;41:113-121

Soderstrom, Staffan T, Petterson, Richard P., Leppert, Jerzy. Prediction of driving ability after stroke and the effect of behind-the-wheel training. Scandinavian Journal of Psychology, 2006;47:419-429

References

Szlyk JP, Brigell M, Seiple W. Effects of age and hemianopic visual field loss on driving. Optom Vis Sci. 1993;70:1031-1037

Tamietto, Marco, Torrini, Gaia, Mauro, Adenzato, Pietrapiana, Paolo, Rago, Roberto, Perino, Claudio. To Drive or not to drive (after TBI)? A review of the literature and its implications for rehabilitation and future research. NeuroRehabilitation 21 (2006) 81-92

Traffic Safety References Traffic Safety Facts 2002: Older Population. US Department of

Transportation, National Highway Traffic Safety Administration. Available at: http://www-fars.nhtsa.dot.gov/pubs/7.pdf. Accessed January 17, 2003.

10 Leading Causes of Injury Deaths, United States, 1999, All Races, Both Sexes. Office of Statistics and Programming, National Center for Injury Prevention and Control, Center for Disease Control. Data source: National Center for Health Statistics Vital Statistics System.

Eberhard J. Safe mobility for senior citizens. International Association for Traffic and Safety Services Research. 1996;20(1):29-37.

Li G, Braver ER, Chen LH. Fragility versus excessive crash involvement as determinants of high death rates per vehicle-mile of travel among older drivers. Accident Analysis and Prevention. 2003;35(2): 227-235.

Preusser DF, Williams AF, Ferguson SA, Ullmer RG, Weinstein HB. Fatal crash risk for older drivers at intersections. Accident Analysis and Prevention. 1998;30(2):151-159.

Traffic Safety References (cont.)

Traffic Safety Facts 2000: A Compilation of Motor Vehicle Crash Data from the Fatality Analysis Reporting System and the General Estimates System. Washington, DC: US Department of Transportation, National Highway Traffic Safety Administration; 2001.

Calculated from reference 7.

Eberhard J. Older Drivers Up Close: They Aren’t Dangerous. Insurance Institute for Highway Safety Status Report (Special Issue: Older Drivers). 2001;36(8):1-2.

Eberhard J. Safe mobility for senior citizens. International Association for Traffic and Safety Services Research.1996;20(1):29-37.

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