SlideShare a Scribd company logo
STEREOPSIS IN INFANTS AND ITS
DEVELOPMENT IN RELATION TO
VISUAL ACUITY
RESHMA S SURESH
Stereopsis
• Clinical tests for stereopsis currently available require verbal interactions that are
unreliable in patients less than 2.5 years of age
•Testing stereopsis in young children is important for assisting in the identification
and progression of amblyopia, strabismus and significant refractive error
•A study by Shea et al. (1980) is based upon generating a random-element
stereogram in real time on a modified color video monitor that presents the
stereogram as an anaglyph
•The stereoscopic form can be moved about in stereoscopic space without the
introduction of monocular cues, and these movements can be used to engage in
infants visual attention
•If the infant’s eye movements and other attentive behavior are correlated with
the movement of the stereoscopic form, then the infant is having the capacity of
stereopsis
•Using this method they have found that stereopsis does not emerge until the
third or fourth postnatal month
•Infants have been reported to respond to coarse disparities present in dynamic
random-dot stereograms by their fourth month of life
•A study by R Held (1980) applied a new procedure using line stereograms
•It showed that stereoacuity of one degree is measurable by the fourth month
and that it rapidly improves to at least one sec of arc by the fifth month
•Stereograms were used in order to eliminate the parallax motion that is
produced by movements of the head in relation to a real object
Visual cliff – Experiment for depth
perception
Visual cliff designed by Eleanor Gibson and Richard Walk (1960) was used in
the studies of depth perception
Their apparatus consisted of a 'bridge' either side of which was a sturdy glass
platform
One side of this had a chequered pattern immediately under the glass (the
'shallow side'). On the other side of the bridge was a 'cliff' - the chequered
pattern was beneath a vertical drop
36 infants ranging in age from six months to 14 months.
Infants were placed at the edge of the visual cliff and had their mother coax
them to crawl on to the glass
The independent variable (IV) was whether the infant was called by its mother
from the cliff side or the shallow side (of the visual cliff apparatus).
The dependent variable (DV) was whether or not the child would crawl to its
mother.
Most infants readily crossed the shallow side and most reacted with fear to the
deep side – indicating infants can perceive depth
6-12 months old infants had extensive visual experience
2-4 months old showed variation in heart rate when directly placed on the
deep side
Stereopsis in infants and its development in relation to visual acuity.pptx
Tests for stereopsis
Name of the test Age
Lang Stereo test (Random dot) 8months – 2.5 years
The TNO test 2.5-3 years
Frisby Stereo test 3-12 years
Titmus fly test 4-18 years
The Randot test 3-15 years
The Lang stereo I and II test
•1983, Joseph Lang
•Stereopsis screening in children
•It is based on random dot principle
•The Lang test card was held by the examiner directly
in front of the child
•Positive responses, demonstrated by correct pointing
or an attempt to grasp one of the shapes
•The patient has to locate Cat (1200 arc sec), Star
(600), Car (550) for Lang I
•The patient has to locate the arc of the moon (200
arc sec), a star (200 arc sec), a car (400 arc sec), and
an elephant (600 arc sec) for Lang II
The TNO test
•Toegepast Natuurwetenschappelijk Onderzoek
•This test was developed for the Dutch military
as a screening test for stereopsis
•It consists of booklet containing seven plates
•Red and green glasses are required to
dissociate
•The first four plates are useful as the disparity
is large and provides a qualitative assessment
of stereopsis
•The fifth and seventh plate grades from 480 to
15 arc sec
The Frisby test
•Three plastic cards each containing four
squares of small random shape one of this
squares in each plate contains a hidden circle
which is seen in disparity
•The disparity is created by displacement of
random shapes by the thickness of the plate so
this test does not require use of glasses
•A disadvantage of this test is that if the plate or
child moves, motion parallax cues can reveal
the disk
•By using plates with three different thicknesses
viewed at nine different distances, 27
disparities between 5 and 600 sec of arc can be
presented
The Titmus fly test
•It consists of Fly, wirt circles, and animals.
•Done at 40cm
•Requires polarized glasses
•The contours of the circles are visible monocularly
especially at high disparities, making it possible
for a stereoblind child to solve atleast some of the
levels
•Sensitivity of Titmus is estimated at 63% for
strabismus and 38% for amblyopia, making the
test unsuitable for screening
•The test-retest repeatability is relatively poor, but
better than TNO test.
The Randot test
•Requires polarized glasses and done at
40 cm
•The test is a contour stereotest with the
associated monocular cues in the high
disparities
•The circles and animal subtests has
monocular cues
•The third subtest does not have
monocular cues
Stereopsis in infants and its development in relation to visual acuity.pptx
Stereopsis in infants and its development in relation to visual acuity.pptx
Are babies born with visual abilities?
 Babies are not born with all the visual abilities they need in life
The ability to focus their eyes, move them accurately and use them together as
a team must be learned
They need to learn how to use the visual information
 From birth - babies begin exploring the wonders in the world with their eyes
Visual acuity, in preverbal infants, is defined as a motor or sensory response to a threshold
stimulus of known size at known testing distance.
Steps in infant visual development
At birth, babies can't see as well as older children or adults.
Their eyes and visual system aren't fully developed.
It is important to remember that not every child is the same and some may
reach certain milestones at different ages.
Newborn’s visual acuity: 20/600. That is a new born can see clearly at 20 feet
what a normal adult can see at 600 feet (Schiffman, 2000)
Birth to four months
At birth - An infant is very sensitive to bright light. A newborn baby can see
something next to them with their peripheral vision, but their central vision is
still developing.
First months of life - eyes start working together and vision rapidly improves
Eye-hand coordination begins to develop as the infant starts tracking moving
objects with his or her eyes and reaching for them
Two months of life - babies begin to more easily focus their eyes on the faces of
a parent or other person near them
An infant's eyes are not well coordinated and may appear to wander or to be
crossed (usually normal)
- If an eye appears to turn in or out constantly - evaluation is warranted
Babies should begin to follow moving objects with their eyes and reach for
things at around three months of age
Stereopsis in infants and its development in relation to visual acuity.pptx
Five to eight months
These months - control of eye movements and eye-body coordination skills
continue to improve
Depth perception which is the ability to judge if objects are nearer or farther
away than other objects (not present at birth)
It is not until around the fifth month that the eyes are capable of working
together to form a three-dimensional view of the world and begin to see in
depth
They get better at reaching for objects both near and far
Infant's color vision is not as sensitive as an adult's - it is generally believed that
babies have good color vision by five months of age
Most babies start crawling at about 8 months old - which helps further develop
eye-hand-foot-body coordination
Nine to twelve months
At around 9 months of age - begin to pull themselves up to a standing position
By 10 months of age a baby should be able to grasp objects with thumb and
forefinger
By twelve months of age - most babies will be crawling and trying to walk
(Parents should encourage crawling rather than early walking to help the child
develop better eye-hand coordination)
Stereopsis in infants and its development in relation to visual acuity.pptx
One to Two years
By two years of age - a child's eye-hand coordination and depth perception should be well
developed
Children this age are highly interested in exploring their environment and in looking and
listening
They recognize familiar objects and pictures in books and can scribble with crayon or pencil.
Stereopsis in infants and its development in relation to visual acuity.pptx
REFERENCES
1. https://www.opticianonline.net/cpd-archive/4723
2. https://www.aoa.org/patients-and-public/good-vision-throughout-life/childrens-
vision/infant-vision-birth-to-24-months-of-age
3. https://www.aao.org/eye-health/tips-prevention/baby-vision-development-first-
year
4. Pediatric ophthalmology and strabismus, Kenneth W. Wright and Peter H Speigel
(second edition)
5. Broadbent H, Westall C. An evaluation of techniques for measuring stereopsis in
infants and young children. Ophthalmic Physiol Opt. 1990 Jan;10(1):3-7. PMID:
2184389
Stereopsis in infants and its development in relation to visual acuity.pptx

More Related Content

What's hot

Coloured contact lens
Coloured contact lensColoured contact lens
Coloured contact lens
farisfrn
 
Development Of Vision
Development Of VisionDevelopment Of Vision
Development Of Vision
Manoj Aryal
 
Tints and filter for patients with low vision
Tints and filter for patients with low visionTints and filter for patients with low vision
Tints and filter for patients with low vision
GauriChaudhary7
 
FDA classification of soft contact lens
FDA classification of soft contact lensFDA classification of soft contact lens
FDA classification of soft contact lens
sushmitha hebri
 
Contact lens
Contact lensContact lens
Contact lens
Prashant Patel
 
Optics of contact lens
Optics of contact lensOptics of contact lens
Optics of contact lens
Aayush Chandan
 
progressive addition lenses- optics, designs and performances
progressive addition lenses- optics, designs and performancesprogressive addition lenses- optics, designs and performances
progressive addition lenses- optics, designs and performances
sabina paudel
 
Binocular refraction techniques, binocular balancing & binocular
Binocular refraction techniques, binocular balancing & binocularBinocular refraction techniques, binocular balancing & binocular
Binocular refraction techniques, binocular balancing & binocular
sabina paudel
 
Orthokeratology_Refractive treatment
Orthokeratology_Refractive treatmentOrthokeratology_Refractive treatment
Orthokeratology_Refractive treatment
Anis Suzanna Mohamad
 
Pediatric optometry
Pediatric optometryPediatric optometry
Pediatric optometry
Mero Eye
 
Various Soft Contact Lens- designs and their indications
Various Soft Contact Lens- designs and their indications Various Soft Contact Lens- designs and their indications
Various Soft Contact Lens- designs and their indications
Urusha Maharjan
 
Aniseikonia
AniseikoniaAniseikonia
Aniseikonia
Aliasger Fakhruddin
 
Prescribing low vision devices by SURAJ CHHETRI
Prescribing low vision devices by SURAJ CHHETRIPrescribing low vision devices by SURAJ CHHETRI
Prescribing low vision devices by SURAJ CHHETRI
Suraj Chhetri
 
Progressive Adition Lens
Progressive Adition LensProgressive Adition Lens
Progressive Adition Lens
Kewal Hirwani
 
A-V pattern strabismus
A-V pattern strabismusA-V pattern strabismus
A-V pattern strabismus
Amrit Pokharel
 
Lens power measurement
Lens power measurementLens power measurement
Lens power measurement
Hossein Mirzaie
 
Soft Toric Contact lens
Soft Toric Contact lensSoft Toric Contact lens
Soft Toric Contact lens
aditi jobaliya vora
 
Ophthalmic Prisms: Prismatic Effects and Decentration
Ophthalmic Prisms: Prismatic Effects and DecentrationOphthalmic Prisms: Prismatic Effects and Decentration
Ophthalmic Prisms: Prismatic Effects and Decentration
RabindraAdhikary
 
disposable contact lenses
disposable contact lensesdisposable contact lenses
disposable contact lenses
Vishakh Nair
 
Bifocal Spectacles..
Bifocal Spectacles..Bifocal Spectacles..
Bifocal Spectacles..
Vishakh Nair
 

What's hot (20)

Coloured contact lens
Coloured contact lensColoured contact lens
Coloured contact lens
 
Development Of Vision
Development Of VisionDevelopment Of Vision
Development Of Vision
 
Tints and filter for patients with low vision
Tints and filter for patients with low visionTints and filter for patients with low vision
Tints and filter for patients with low vision
 
FDA classification of soft contact lens
FDA classification of soft contact lensFDA classification of soft contact lens
FDA classification of soft contact lens
 
Contact lens
Contact lensContact lens
Contact lens
 
Optics of contact lens
Optics of contact lensOptics of contact lens
Optics of contact lens
 
progressive addition lenses- optics, designs and performances
progressive addition lenses- optics, designs and performancesprogressive addition lenses- optics, designs and performances
progressive addition lenses- optics, designs and performances
 
Binocular refraction techniques, binocular balancing & binocular
Binocular refraction techniques, binocular balancing & binocularBinocular refraction techniques, binocular balancing & binocular
Binocular refraction techniques, binocular balancing & binocular
 
Orthokeratology_Refractive treatment
Orthokeratology_Refractive treatmentOrthokeratology_Refractive treatment
Orthokeratology_Refractive treatment
 
Pediatric optometry
Pediatric optometryPediatric optometry
Pediatric optometry
 
Various Soft Contact Lens- designs and their indications
Various Soft Contact Lens- designs and their indications Various Soft Contact Lens- designs and their indications
Various Soft Contact Lens- designs and their indications
 
Aniseikonia
AniseikoniaAniseikonia
Aniseikonia
 
Prescribing low vision devices by SURAJ CHHETRI
Prescribing low vision devices by SURAJ CHHETRIPrescribing low vision devices by SURAJ CHHETRI
Prescribing low vision devices by SURAJ CHHETRI
 
Progressive Adition Lens
Progressive Adition LensProgressive Adition Lens
Progressive Adition Lens
 
A-V pattern strabismus
A-V pattern strabismusA-V pattern strabismus
A-V pattern strabismus
 
Lens power measurement
Lens power measurementLens power measurement
Lens power measurement
 
Soft Toric Contact lens
Soft Toric Contact lensSoft Toric Contact lens
Soft Toric Contact lens
 
Ophthalmic Prisms: Prismatic Effects and Decentration
Ophthalmic Prisms: Prismatic Effects and DecentrationOphthalmic Prisms: Prismatic Effects and Decentration
Ophthalmic Prisms: Prismatic Effects and Decentration
 
disposable contact lenses
disposable contact lensesdisposable contact lenses
disposable contact lenses
 
Bifocal Spectacles..
Bifocal Spectacles..Bifocal Spectacles..
Bifocal Spectacles..
 

Similar to Stereopsis in infants and its development in relation to visual acuity.pptx

Studies of abnormal visual development
Studies of abnormal visual developmentStudies of abnormal visual development
Studies of abnormal visual development
Hossein Mirzaie
 
Development of Vision
Development of VisionDevelopment of Vision
Development of Vision
CSN Vittal
 
Growth and development
Growth and developmentGrowth and development
Growth and development
Grace Escarcha
 
A STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACE
A STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACEA STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACE
A STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACE
The Open University of Sri Lanka
 
Development of Vision
Development of VisionDevelopment of Vision
Development of Vision
Rabia Ammer
 
My ppt
My pptMy ppt
My ppt
Hira Dahal
 
Early childhood development
Early childhood developmentEarly childhood development
Early childhood development
Jocelle Macariola
 
Earlychildhooddevelopment
EarlychildhooddevelopmentEarlychildhooddevelopment
Earlychildhooddevelopment
Danny Maribao
 
Eye and vision at birth and childhood
Eye and vision at birth and childhoodEye and vision at birth and childhood
Eye and vision at birth and childhood
Manoj Mahat
 
3.pediatric development
3.pediatric development3.pediatric development
3.pediatric development
Francis Joshi
 
PerceptualDevelopment.pptx
PerceptualDevelopment.pptxPerceptualDevelopment.pptx
PerceptualDevelopment.pptx
HEMANTBUNKER2
 
Development short cases approach
Development short cases  approachDevelopment short cases  approach
Development short cases approach
Teik Beng Khoo
 
SENSE OF SIGHT
SENSE OF SIGHTSENSE OF SIGHT
SENSE OF SIGHT
Julienne Mae Valdez
 
developmental milestones assessment.pptx
developmental milestones assessment.pptxdevelopmental milestones assessment.pptx
developmental milestones assessment.pptx
Israa Dfallah
 
Pediatric rotation
Pediatric rotationPediatric rotation
Pediatric rotation
anishkumar123
 
Visual acuity assessment in paediatric patients.pptx2222
Visual acuity assessment in paediatric patients.pptx2222Visual acuity assessment in paediatric patients.pptx2222
Visual acuity assessment in paediatric patients.pptx2222
Anisha Rathod
 
prof-ed-1.pptx
prof-ed-1.pptxprof-ed-1.pptx
prof-ed-1.pptx
CarlAbrera
 
Infancy.ppt. .
Infancy.ppt.                            .Infancy.ppt.                            .
Infancy.ppt. .
MadhuSM4
 
UNIT 4.pptx
UNIT 4.pptxUNIT 4.pptx
UNIT 4.pptx
GeraldSantillana
 
Visual development basics
Visual development basics Visual development basics
Visual development basics
Sachitanand Singh
 

Similar to Stereopsis in infants and its development in relation to visual acuity.pptx (20)

Studies of abnormal visual development
Studies of abnormal visual developmentStudies of abnormal visual development
Studies of abnormal visual development
 
Development of Vision
Development of VisionDevelopment of Vision
Development of Vision
 
Growth and development
Growth and developmentGrowth and development
Growth and development
 
A STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACE
A STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACEA STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACE
A STUDY ON SRI LANKAN CHILDREN’S CONCEPTION OF SPACE
 
Development of Vision
Development of VisionDevelopment of Vision
Development of Vision
 
My ppt
My pptMy ppt
My ppt
 
Early childhood development
Early childhood developmentEarly childhood development
Early childhood development
 
Earlychildhooddevelopment
EarlychildhooddevelopmentEarlychildhooddevelopment
Earlychildhooddevelopment
 
Eye and vision at birth and childhood
Eye and vision at birth and childhoodEye and vision at birth and childhood
Eye and vision at birth and childhood
 
3.pediatric development
3.pediatric development3.pediatric development
3.pediatric development
 
PerceptualDevelopment.pptx
PerceptualDevelopment.pptxPerceptualDevelopment.pptx
PerceptualDevelopment.pptx
 
Development short cases approach
Development short cases  approachDevelopment short cases  approach
Development short cases approach
 
SENSE OF SIGHT
SENSE OF SIGHTSENSE OF SIGHT
SENSE OF SIGHT
 
developmental milestones assessment.pptx
developmental milestones assessment.pptxdevelopmental milestones assessment.pptx
developmental milestones assessment.pptx
 
Pediatric rotation
Pediatric rotationPediatric rotation
Pediatric rotation
 
Visual acuity assessment in paediatric patients.pptx2222
Visual acuity assessment in paediatric patients.pptx2222Visual acuity assessment in paediatric patients.pptx2222
Visual acuity assessment in paediatric patients.pptx2222
 
prof-ed-1.pptx
prof-ed-1.pptxprof-ed-1.pptx
prof-ed-1.pptx
 
Infancy.ppt. .
Infancy.ppt.                            .Infancy.ppt.                            .
Infancy.ppt. .
 
UNIT 4.pptx
UNIT 4.pptxUNIT 4.pptx
UNIT 4.pptx
 
Visual development basics
Visual development basics Visual development basics
Visual development basics
 

More from reshmasu

GRANT WRITING.pptx
GRANT WRITING.pptxGRANT WRITING.pptx
GRANT WRITING.pptx
reshmasu
 
COHORT STUDIES.pptx
COHORT STUDIES.pptxCOHORT STUDIES.pptx
COHORT STUDIES.pptx
reshmasu
 
DIABETIC RETINOPATHY.pptx
DIABETIC RETINOPATHY.pptxDIABETIC RETINOPATHY.pptx
DIABETIC RETINOPATHY.pptx
reshmasu
 
DIABETES MELLITUS AND VISUAL IMPAIRMENT.pptx
DIABETES MELLITUS AND VISUAL IMPAIRMENT.pptxDIABETES MELLITUS AND VISUAL IMPAIRMENT.pptx
DIABETES MELLITUS AND VISUAL IMPAIRMENT.pptx
reshmasu
 
Alzhiemer’s diseases.pptx
Alzhiemer’s diseases.pptxAlzhiemer’s diseases.pptx
Alzhiemer’s diseases.pptx
reshmasu
 
VITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptx
VITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptxVITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptx
VITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptx
reshmasu
 
EXOTROPIA.pptx
EXOTROPIA.pptxEXOTROPIA.pptx
EXOTROPIA.pptx
reshmasu
 
CARE AND MAINTANENCE OF SOFT CONTACT LENS.pptx
CARE AND MAINTANENCE OF SOFT CONTACT LENS.pptxCARE AND MAINTANENCE OF SOFT CONTACT LENS.pptx
CARE AND MAINTANENCE OF SOFT CONTACT LENS.pptx
reshmasu
 

More from reshmasu (8)

GRANT WRITING.pptx
GRANT WRITING.pptxGRANT WRITING.pptx
GRANT WRITING.pptx
 
COHORT STUDIES.pptx
COHORT STUDIES.pptxCOHORT STUDIES.pptx
COHORT STUDIES.pptx
 
DIABETIC RETINOPATHY.pptx
DIABETIC RETINOPATHY.pptxDIABETIC RETINOPATHY.pptx
DIABETIC RETINOPATHY.pptx
 
DIABETES MELLITUS AND VISUAL IMPAIRMENT.pptx
DIABETES MELLITUS AND VISUAL IMPAIRMENT.pptxDIABETES MELLITUS AND VISUAL IMPAIRMENT.pptx
DIABETES MELLITUS AND VISUAL IMPAIRMENT.pptx
 
Alzhiemer’s diseases.pptx
Alzhiemer’s diseases.pptxAlzhiemer’s diseases.pptx
Alzhiemer’s diseases.pptx
 
VITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptx
VITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptxVITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptx
VITREOUS AND RETINA PEDIATRIC OCULAR DIESEASES.pptx
 
EXOTROPIA.pptx
EXOTROPIA.pptxEXOTROPIA.pptx
EXOTROPIA.pptx
 
CARE AND MAINTANENCE OF SOFT CONTACT LENS.pptx
CARE AND MAINTANENCE OF SOFT CONTACT LENS.pptxCARE AND MAINTANENCE OF SOFT CONTACT LENS.pptx
CARE AND MAINTANENCE OF SOFT CONTACT LENS.pptx
 

Recently uploaded

A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715
A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715
A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715
Sérgio Sacani
 
Composting blue materials - Joshua Cabell
Composting blue materials - Joshua CabellComposting blue materials - Joshua Cabell
Composting blue materials - Joshua Cabell
Faculty of Applied Chemistry and Materials Science
 
NuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdfNuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdf
pablovgd
 
Ancient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , BiogenesisAncient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , Biogenesis
SoniaBajaj10
 
16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf
16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf
16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf
marigreenproject
 
ellipticytescausesprognosistreatment-240622051139-23d50b05.pptx
ellipticytescausesprognosistreatment-240622051139-23d50b05.pptxellipticytescausesprognosistreatment-240622051139-23d50b05.pptx
ellipticytescausesprognosistreatment-240622051139-23d50b05.pptx
muralinath2
 
Classification and role of plant nutrients - Roxana Madjar
Classification and role of plant nutrients - Roxana MadjarClassification and role of plant nutrients - Roxana Madjar
Classification and role of plant nutrients - Roxana Madjar
Faculty of Applied Chemistry and Materials Science
 
Potential of Marine Renewable and Non renewable energy.pptx
Potential of Marine Renewable and Non renewable energy.pptxPotential of Marine Renewable and Non renewable energy.pptx
Potential of Marine Renewable and Non renewable energy.pptx
J. Bovas Joel BFSc
 
VIII-Geography FOR CBSE CLASS 8 INDIA.pdf
VIII-Geography FOR CBSE CLASS 8 INDIA.pdfVIII-Geography FOR CBSE CLASS 8 INDIA.pdf
VIII-Geography FOR CBSE CLASS 8 INDIA.pdf
poorvarajgolkar
 
How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?
How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?
How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?
Christian Birchler
 
Traditional, current and future use of fish and seaweed for fertilisation - ...
Traditional, current and future use of fish and seaweed for fertilisation -  ...Traditional, current and future use of fish and seaweed for fertilisation -  ...
Traditional, current and future use of fish and seaweed for fertilisation - ...
Faculty of Applied Chemistry and Materials Science
 
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Sérgio Sacani
 
Rice Genome Project a complete saga .(1).pptx
Rice Genome  Project a complete saga .(1).pptxRice Genome  Project a complete saga .(1).pptx
Rice Genome Project a complete saga .(1).pptx
SoumyaDixit11
 
Speed-accuracy trade-off for the diffusion models
Speed-accuracy trade-off for the diffusion modelsSpeed-accuracy trade-off for the diffusion models
Speed-accuracy trade-off for the diffusion models
sosukeito
 
Potential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptxPotential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptx
J. Bovas Joel BFSc
 
Post RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) MetabolismPost RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) Metabolism
Areesha Ahmad
 
MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)
MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)
MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)
Steffi Friedrichs
 
Current Electricity MCQ Class XII. Physics pptx
Current Electricity MCQ Class XII. Physics pptxCurrent Electricity MCQ Class XII. Physics pptx
Current Electricity MCQ Class XII. Physics pptx
ArunachalamM22
 
Complementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotailComplementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotail
Sérgio Sacani
 
Bioconversion of sago waste and oil cakes into biobutanol using Environmental...
Bioconversion of sago waste and oil cakes into biobutanol using Environmental...Bioconversion of sago waste and oil cakes into biobutanol using Environmental...
Bioconversion of sago waste and oil cakes into biobutanol using Environmental...
Dr NEETHU ASOKAN
 

Recently uploaded (20)

A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715
A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715
A NICER VIEW OF THE NEAREST AND BRIGHTEST MILLISECOND PULSAR: PSR J0437−4715
 
Composting blue materials - Joshua Cabell
Composting blue materials - Joshua CabellComposting blue materials - Joshua Cabell
Composting blue materials - Joshua Cabell
 
NuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdfNuGOweek 2024 Ghent programme__flyer.pdf
NuGOweek 2024 Ghent programme__flyer.pdf
 
Ancient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , BiogenesisAncient Theory, Abiogenesis , Biogenesis
Ancient Theory, Abiogenesis , Biogenesis
 
16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf
16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf
16. 20240529_Ailin Molosag_MARIGREEN_SS_Day3_Ailin.pdf
 
ellipticytescausesprognosistreatment-240622051139-23d50b05.pptx
ellipticytescausesprognosistreatment-240622051139-23d50b05.pptxellipticytescausesprognosistreatment-240622051139-23d50b05.pptx
ellipticytescausesprognosistreatment-240622051139-23d50b05.pptx
 
Classification and role of plant nutrients - Roxana Madjar
Classification and role of plant nutrients - Roxana MadjarClassification and role of plant nutrients - Roxana Madjar
Classification and role of plant nutrients - Roxana Madjar
 
Potential of Marine Renewable and Non renewable energy.pptx
Potential of Marine Renewable and Non renewable energy.pptxPotential of Marine Renewable and Non renewable energy.pptx
Potential of Marine Renewable and Non renewable energy.pptx
 
VIII-Geography FOR CBSE CLASS 8 INDIA.pdf
VIII-Geography FOR CBSE CLASS 8 INDIA.pdfVIII-Geography FOR CBSE CLASS 8 INDIA.pdf
VIII-Geography FOR CBSE CLASS 8 INDIA.pdf
 
How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?
How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?
How Does Simulation-Based Testing for Self-Driving Cars Match Human Perception?
 
Traditional, current and future use of fish and seaweed for fertilisation - ...
Traditional, current and future use of fish and seaweed for fertilisation -  ...Traditional, current and future use of fish and seaweed for fertilisation -  ...
Traditional, current and future use of fish and seaweed for fertilisation - ...
 
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...Surface properties of the seas of Titan as revealed by Cassini mission bistat...
Surface properties of the seas of Titan as revealed by Cassini mission bistat...
 
Rice Genome Project a complete saga .(1).pptx
Rice Genome  Project a complete saga .(1).pptxRice Genome  Project a complete saga .(1).pptx
Rice Genome Project a complete saga .(1).pptx
 
Speed-accuracy trade-off for the diffusion models
Speed-accuracy trade-off for the diffusion modelsSpeed-accuracy trade-off for the diffusion models
Speed-accuracy trade-off for the diffusion models
 
Potential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptxPotential of Marine renewable and Non renewable energy.pptx
Potential of Marine renewable and Non renewable energy.pptx
 
Post RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) MetabolismPost RN - Biochemistry (Unit 7) Metabolism
Post RN - Biochemistry (Unit 7) Metabolism
 
MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)
MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)
MACRAMÉ ChIPs @Behoerdenklausur 2024 (Berlin)
 
Current Electricity MCQ Class XII. Physics pptx
Current Electricity MCQ Class XII. Physics pptxCurrent Electricity MCQ Class XII. Physics pptx
Current Electricity MCQ Class XII. Physics pptx
 
Complementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotailComplementary interstellar detections from the heliotail
Complementary interstellar detections from the heliotail
 
Bioconversion of sago waste and oil cakes into biobutanol using Environmental...
Bioconversion of sago waste and oil cakes into biobutanol using Environmental...Bioconversion of sago waste and oil cakes into biobutanol using Environmental...
Bioconversion of sago waste and oil cakes into biobutanol using Environmental...
 

Stereopsis in infants and its development in relation to visual acuity.pptx

  • 1. STEREOPSIS IN INFANTS AND ITS DEVELOPMENT IN RELATION TO VISUAL ACUITY RESHMA S SURESH
  • 2. Stereopsis • Clinical tests for stereopsis currently available require verbal interactions that are unreliable in patients less than 2.5 years of age •Testing stereopsis in young children is important for assisting in the identification and progression of amblyopia, strabismus and significant refractive error •A study by Shea et al. (1980) is based upon generating a random-element stereogram in real time on a modified color video monitor that presents the stereogram as an anaglyph •The stereoscopic form can be moved about in stereoscopic space without the introduction of monocular cues, and these movements can be used to engage in infants visual attention
  • 3. •If the infant’s eye movements and other attentive behavior are correlated with the movement of the stereoscopic form, then the infant is having the capacity of stereopsis •Using this method they have found that stereopsis does not emerge until the third or fourth postnatal month •Infants have been reported to respond to coarse disparities present in dynamic random-dot stereograms by their fourth month of life •A study by R Held (1980) applied a new procedure using line stereograms •It showed that stereoacuity of one degree is measurable by the fourth month and that it rapidly improves to at least one sec of arc by the fifth month •Stereograms were used in order to eliminate the parallax motion that is produced by movements of the head in relation to a real object
  • 4. Visual cliff – Experiment for depth perception Visual cliff designed by Eleanor Gibson and Richard Walk (1960) was used in the studies of depth perception Their apparatus consisted of a 'bridge' either side of which was a sturdy glass platform One side of this had a chequered pattern immediately under the glass (the 'shallow side'). On the other side of the bridge was a 'cliff' - the chequered pattern was beneath a vertical drop 36 infants ranging in age from six months to 14 months. Infants were placed at the edge of the visual cliff and had their mother coax them to crawl on to the glass
  • 5. The independent variable (IV) was whether the infant was called by its mother from the cliff side or the shallow side (of the visual cliff apparatus). The dependent variable (DV) was whether or not the child would crawl to its mother. Most infants readily crossed the shallow side and most reacted with fear to the deep side – indicating infants can perceive depth 6-12 months old infants had extensive visual experience 2-4 months old showed variation in heart rate when directly placed on the deep side
  • 7. Tests for stereopsis Name of the test Age Lang Stereo test (Random dot) 8months – 2.5 years The TNO test 2.5-3 years Frisby Stereo test 3-12 years Titmus fly test 4-18 years The Randot test 3-15 years
  • 8. The Lang stereo I and II test •1983, Joseph Lang •Stereopsis screening in children •It is based on random dot principle •The Lang test card was held by the examiner directly in front of the child •Positive responses, demonstrated by correct pointing or an attempt to grasp one of the shapes •The patient has to locate Cat (1200 arc sec), Star (600), Car (550) for Lang I •The patient has to locate the arc of the moon (200 arc sec), a star (200 arc sec), a car (400 arc sec), and an elephant (600 arc sec) for Lang II
  • 9. The TNO test •Toegepast Natuurwetenschappelijk Onderzoek •This test was developed for the Dutch military as a screening test for stereopsis •It consists of booklet containing seven plates •Red and green glasses are required to dissociate •The first four plates are useful as the disparity is large and provides a qualitative assessment of stereopsis •The fifth and seventh plate grades from 480 to 15 arc sec
  • 10. The Frisby test •Three plastic cards each containing four squares of small random shape one of this squares in each plate contains a hidden circle which is seen in disparity •The disparity is created by displacement of random shapes by the thickness of the plate so this test does not require use of glasses •A disadvantage of this test is that if the plate or child moves, motion parallax cues can reveal the disk •By using plates with three different thicknesses viewed at nine different distances, 27 disparities between 5 and 600 sec of arc can be presented
  • 11. The Titmus fly test •It consists of Fly, wirt circles, and animals. •Done at 40cm •Requires polarized glasses •The contours of the circles are visible monocularly especially at high disparities, making it possible for a stereoblind child to solve atleast some of the levels •Sensitivity of Titmus is estimated at 63% for strabismus and 38% for amblyopia, making the test unsuitable for screening •The test-retest repeatability is relatively poor, but better than TNO test.
  • 12. The Randot test •Requires polarized glasses and done at 40 cm •The test is a contour stereotest with the associated monocular cues in the high disparities •The circles and animal subtests has monocular cues •The third subtest does not have monocular cues
  • 15. Are babies born with visual abilities?  Babies are not born with all the visual abilities they need in life The ability to focus their eyes, move them accurately and use them together as a team must be learned They need to learn how to use the visual information  From birth - babies begin exploring the wonders in the world with their eyes
  • 16. Visual acuity, in preverbal infants, is defined as a motor or sensory response to a threshold stimulus of known size at known testing distance.
  • 17. Steps in infant visual development At birth, babies can't see as well as older children or adults. Their eyes and visual system aren't fully developed. It is important to remember that not every child is the same and some may reach certain milestones at different ages. Newborn’s visual acuity: 20/600. That is a new born can see clearly at 20 feet what a normal adult can see at 600 feet (Schiffman, 2000)
  • 18. Birth to four months At birth - An infant is very sensitive to bright light. A newborn baby can see something next to them with their peripheral vision, but their central vision is still developing. First months of life - eyes start working together and vision rapidly improves Eye-hand coordination begins to develop as the infant starts tracking moving objects with his or her eyes and reaching for them
  • 19. Two months of life - babies begin to more easily focus their eyes on the faces of a parent or other person near them An infant's eyes are not well coordinated and may appear to wander or to be crossed (usually normal) - If an eye appears to turn in or out constantly - evaluation is warranted Babies should begin to follow moving objects with their eyes and reach for things at around three months of age
  • 21. Five to eight months These months - control of eye movements and eye-body coordination skills continue to improve Depth perception which is the ability to judge if objects are nearer or farther away than other objects (not present at birth) It is not until around the fifth month that the eyes are capable of working together to form a three-dimensional view of the world and begin to see in depth They get better at reaching for objects both near and far
  • 22. Infant's color vision is not as sensitive as an adult's - it is generally believed that babies have good color vision by five months of age Most babies start crawling at about 8 months old - which helps further develop eye-hand-foot-body coordination
  • 23. Nine to twelve months At around 9 months of age - begin to pull themselves up to a standing position By 10 months of age a baby should be able to grasp objects with thumb and forefinger By twelve months of age - most babies will be crawling and trying to walk (Parents should encourage crawling rather than early walking to help the child develop better eye-hand coordination)
  • 25. One to Two years By two years of age - a child's eye-hand coordination and depth perception should be well developed Children this age are highly interested in exploring their environment and in looking and listening They recognize familiar objects and pictures in books and can scribble with crayon or pencil.
  • 27. REFERENCES 1. https://www.opticianonline.net/cpd-archive/4723 2. https://www.aoa.org/patients-and-public/good-vision-throughout-life/childrens- vision/infant-vision-birth-to-24-months-of-age 3. https://www.aao.org/eye-health/tips-prevention/baby-vision-development-first- year 4. Pediatric ophthalmology and strabismus, Kenneth W. Wright and Peter H Speigel (second edition) 5. Broadbent H, Westall C. An evaluation of techniques for measuring stereopsis in infants and young children. Ophthalmic Physiol Opt. 1990 Jan;10(1):3-7. PMID: 2184389

Editor's Notes

  1. HERE SUBJECTIVE RESPONSE IS IMPORTANT. Computerized stereogram, TNO test presented in difficulty in testing infants between 8 months and 2 years because of the likelihood that these children would reject the red/green glasses.