Vision problem

DefinitionOcular disease and disorder Occupational therapy evaluationSigns and symptoms of visual problemOccupational therapy intervention Effect of vision problem on…

The Eye – How sight occurs???

Definition:

• Visual impairment : loss or deficits in visual function (vision, visual perception; interpretation of visual input ) due to pathology or processing problem in one or more component of the visual system (structure of the eye, visual pathway, and the brain) that limits the individual ability to engage in participation in daily occupation.

Ocular disease and disorder Condition Affected area cause Visual affects

Degenerative myopia

Elongation of the eye; cornea steeply curved; stretching of the posterior of the eye.

Heredity Decreased visual acuity in the distant things Photophobia; light sensitivity

Down syndrome Various parts of the eye

heredityChromosome no 21Trisomy 21

Decreased visual acuity

Retinal detachment Retina separates from the back of the eye

Numerous, including diabetes, Degenerative myopia

Visual field loss, color defect

Achromatopsia (total color blindness)

Retina (cone malformation )

heredityDecreased visual acuity .. Visual fields are normal

condition Affected area cause Visual affect

Cataracts Lens becomes cloudy and less transparent

Heredity and aging blurred vision, nystagmus, decreased visual acuity, visual field is normal

Rubella Various parts of the eye

Virus transmitted to the fetus by the mother during pregnancy

Congenital glaucoma, congenital cataract, decreased visual acuity, and constriction of the visual fields

Hemianopsia Posterior portion of the brain; optic tract

Most common causes: stroke, brain tumor, trauma

Central and/or peripheral visual fields in one or both eyes

Occupational therapy evaluationOccupational therapist focuses on …. Depending

on the client’s age and needs: Participation on play (especially children) Self careSchool occupationPreparation for work

Occupational therapist evaluates Performance skills that support or limit

the client’s ability to engage in specific activities in the following areas:Activity demandClient factorContext, in which the client performs these

activities

Occupational therapy evaluation

Occupational therapy evaluationData collection methods•Occupational therapist can gather information about the child's temperament , self-regulation capacities, sensory processing, sensory modulation behavior & interaction with caregivers through:

– skilled observation– parent or caregiver questionnaires

Signs and symptoms of visual problemCategory Signs and symptoms

physical Eyes are not able to follow moving objects, eyes are not in alignment, blurred vision or double vision, sensitivity to light

behavioral Turn or tilt head when looking at details, become tired after work, poor attention span, cover or close one eye when looking at details, excessive head movement

Performance Appears clumsy, difficulty learning left and right, read slowly

Social Lack of interest in the environment, anxiety, social isolation, decreased self confidence

Occupational therapy intervention • Occupational therapist often provides service to

achieve the following goals:Develop self care skills: OT may consult with and

educate those who work with the child visual impairment to identify skill levels and explain problems affecting the child's development of self care skills.

-Modification and adaptation to the environment . Examples???

Enhance the postural control and movement in space .. The child can use push toys, riding toys, etc.

Develop body awareness and spatial orientation.

Develop tactile- proprioceptive perceptual abilities, the child with visual impairment needs to maximize tactile discrimination abilities to learn about the features and properties of objects; to adjust grasp according to the size, shape, and weight….

Improve manipulation and fine motor skill

Encourage acceptable behavior skill (be active NOT passive)children with visual impairment are at

disadvantage in asocial situation, particularly at school, where typical children are active and often participate in a variety of physical games.

Strengthen cognitive skills, such as cause and effect, object recognition, and ability to match and sort.

Maximize use of functional visionOT should always facilitate the child's use of

whatever vision is available during intervention and every day activities.

• Dynavision technology (video)

Effect of vision problem on

Ocular motor control Visual motor integration Visual spatial relationship Visual form constancy visual figure ground discrimination Visual closureVisual memory_ sequential memory

Vision & ocular motor control

• What is it? • Vision is the act or power of sensing with the

eyes. The visual system is a neutral network that consists of two information-gathering device (the eye) which must co-ordinate effortlessly to obtain a single unified and clear image for transmission via the optic nerves to the visual cortex.

Conti…• Why is it important ?• Links bet. The ocular motor system & the tactile &

proprioceptive system also provide accurate spatial information to allow correct and efficient body posturing and motor control.

• What are the implications? Students with vision and ocular-motor problems may have

difficulties with: Visual stress (headaches; eye strain) Discomfort with close work Fatigues Distractibility when work Abnormal postures when reading or writing often with very

short working distance

Conti…Blurring and\or doubling of print – particularly

when tired.Poor copying, either from book to paper or

from board to paper.Poor reading comprehension or accuracy .Handwriting – poor spacing .Slow spilling.Poor coordination in ball games, team games

or in spatial awareness.

Remediation activities for ocular motor control :

Looking up, down, left and right with the eyes only and no head movement (10 times at the start of a lesson) to stimulate simple eye tracking.

Reading first and last letters on every line of a page of text or the first letter of every word to develop eye movement needed for reading.

Encourage pattern copying. Using increasingly complex shapes to develop visual analysis skills.

Word searcher, pattern games.Experiment with different colored overlays to

minimize visual stress.

Visual motor integration

• What is it?• Visual motor integration is the degree to

which visual perception and fingerـhand movements are well coـordinated in order to translate visual information into a motor response.

• Why is it important?• It is the foundation for the development and

refinement of handwriting and graphic skills.

Conti…• What are the implications?Students with visual motor integration problems

may have difficulties with:handwriting and recording tasks although verbal

skills are good.copying either from book to paper or from board

to paper. graphics and drawing tasks. spacing and staying on lines. presentation of work, e.g. labelling diagrams and

maps.

Conti…

.inaccurate erasing of own workـ performing practical activities, e.g. usingـ

scissors or microscope, building models..manipulating instrumentsـ ,Physical exercise, e.g. ball skills, team gamesـ

handy work.

Remediation activities for visual motor integration

.origami, paper folding, craft activitiesـ.copying drawing and locating grid positionsـ.find the shortest route on maps/mazeـ.tracing activitiesـ.word searchesـ

Visual spatial relationships

• What are they?• Visual spatial perception provides us with

information about the position of two or more objects in relation to self and each another.

• Why is it important?• Some students experience difficulty in

appreciating and processing spatial information from their environment. Inadequate spatial perception has an impact on a student learning

Conti….• What are the implications ? Student with visual spatial relationship

problem may experience difficulties with:Managing stairs , curves, etc.Moving in space.Learning left\right.Reversing letters \ numbers .Horizontal and vertical scanning.

Conti….• Remediation activities for visual spatial

relationships:Mazes, dot to dot, word searches.Copying activities.Drawing simple maps.Reading grid references on maps using

vertical and linear scanning.Using 1 cm squared paper to draw lines from

one point to another, gradually reducing the size of square.

Visual form constancy • What is it ?• Is the ability to recognize the fact that a shape remains

the same despite changes in size, direction orientation and distance,

• Visual memory, figure ground skills and visual discrimination may all contribute to establishing form constancy.

• Why is it important ?• It represents the ability of the individual to interpret

the environment consistently and accurately regardless of changes in presentation of the information.

Conti…..• What are the implications?Student with visual form constancy problem

may experience difficulties with:Categorizing and classifying object\shapes\

materials;Sorting, especially when orientation and

shape changesTransferring from printed to cursive writing .Copying from a book.

Conti…• Remediation activates for visual form constancy :Present the same word in many different styles,

type, colors, fonts together with other word. Encourage student to underline the same word presented in many different forms.

Frequently demonstrate how horizontally presented material looks when presented vertically.

Use orientation of objects visual cue cards to identify objects seen from different angles. E.g. from above, behind, in front,

Visual figure ground discrimination

• What is it?• Visual figure ground discrimination is the

ability to identify relevant information from a background that contains irrelevant or distracting objects\image.

• Why is it important?• It is the ability to screen out irrelevant visual

material in order to concentrate on the important stimulus.

Conti…• What are the implications? Student with visual figure ground discrimination

problem may experience difficulties with:Attending to task.Ignoring what is irrelevant.Shifting attention appropriately.Keeping place when reading, completing a

worksheet or copying work from book or board.Completing all sections in written assignments.

Conti…..Remediation activities for visual figure ground

discrimination :Circling the same word in a text.Word searches.Puzzles.

Visual closure• Definition: is the ability to see in the minds eye

the whole of an object when part of it is hidden.• Why is it important?• It is a foundation skill for fluency and speed in

reading and spilling.• What are the implications?• Student with visual closer problems may

experience difficulties with :Identifying a visual object from an incomplete or

unclear representation.

Conti… Putting parts together to form a whole . Spilling pattern. Mathematical calculation and multiplication tables. Categorizing time and space.

Remediation activities for visual closure: Manipulating and rotating shapes\objects when discussing

their properties. Finishing incomplete pictures gradually reducing given

prompts Drawing a picture\shape\object then rotating it through 90

degrees – drawing it upside down highlight lower half,. Transferring a design shape from one grid to another.

Visual memory\sequential memory Is the ability to remember what is seen and to

recall visual images of objects , shapes, symbols and movement. It is the term used to describe how memory activity processes visual information from short-term recall into long-term store.

Why is it important ?It is foundation of all learning and essential for

accuracy in copying tasks. •

Conti…• What are the implications? Student with visual memory\sequential memory

problem may experience difficulties with:Remembering visual sequences and letter

shapes.Orientation of letters or numbers.Organizing work.Making note.Remembering the sequence from a practical

demonstration.

Conti….• Remediation activities for visual memory \

visual sequential memory word searches\ find the differences.Timed exercise copying from board to paper.

Games with children#visual discrimination• Can you find 10 differences in these two

pictures?

Visual Memory

Figure Ground • How many horses in this picture?

Visual Closure

• Can you recognize the animals in the following picture, even though most of the lines in the picture have been removed?

• If you can, it means you have good visual closure skills!

Lab Exercise

• Split in groups • Develop your own visual perceptual worksheets:– Visual form constancy– Visual sequential memory– Visual figure-ground – Visual closure– Visual spatial relations– Visual motor integration– Visual discrimination