Development of Eye and Vision at different ages

1. DEVELOPMENT OF EYE &
VISION
Rabia Ammer
BSc. (Optom.), M.Phil (Optom.)
Gold Medalist

2. Development of Eye
• The eye begins to develop as a pair of optic
vesicles on each side of the forebrain at the
end of the 4th week of pregnancy.
• Optic vesicles are out growings of the brain
which make contact with the surface
ectoderm and this contact induces changes
necessary for further development of the eye.

3. • Through a groove at the bottom of the optic
vesicle known as choroid fissure the blood
vessels enter the eye.
• Several layers such as the neural tube, neural
crest, surface ectoderm,
and mesoderm contribute to the
development of the eye

4. Neural Tube Ectoderm
(Neuroectoderm)
• Neuroectoderm gives rise to the following
compartments of the eye:
• Retina
• Epithelial lining of Ciliary body and Iris
• Optic nerves
• vitreous

5. Surface Ectoderm
• Surface ectoderm produces the following
parts:
• Lens
• corneal epithelium

6. Neural crest
• Neural crest cells are themselves derived from
the ectoderm and lie close to the neural tube
and form:
• Sclera
• Corneal stroma and endothelium
• Connective tissue and bony structure of the
orbit

7. Mesoderm
• Mesoderm contributes to the following
structures:
• Extraocular muscles
• Endothelial lining of blood vessels of the eye
• sclera & choroid

8. Physical Condition Of The
Eye Before And After Birth

9. Intra uterine
The eyelids are not fully separated.
The pupil does not constrict or dilate; the
aqueous drainage system may not be fully
functional.
The choroid lacks pigment.

10. Intra uterine
Retinal blood vessels are immature.
Optic nerve may not be myelinated.
Lack of ability to control light entering the eye that
the visual system is not ready to function.

11. At Birth
 The irises of infants may have a grey or
bluish appearance; natural color develops as
pigment forms.
 The eyes' pupils are not able to dilate fully
yet.
 The curvature of the lens is nearly spherical.
 The retina is not fully developed.

12. • Infants' eyes develop significantly after birth.
The muscles of the eye such as ciliary muscles
– become stronger after two months of age,
allowing infants to focus on particular objects
through contraction and relaxation.

13. Axial length
• It is important to note that the distance from
the cornea at the front of the infant’s eye to
the retina which is at the back of eye is 16–
17 mm at birth,
• 20 to 21 mm at one year, and
• 23–25 mm in adolescence and adulthood.
• The retinal images are also smaller compared
to adults due to shorter distances from
the retina to the cornea of the infants' eye.

14. • Volume doubles by age 1 yr (10.3-22.3
cu.mm) 39.1 by age 6 (adult 59.2 cu.mm)
• Palpaberal fissure width is less as
compared to vertical dimension (oval
appearance)
• Excretory and secretory function are
present
• Now it is proven that 80% of infant have
normal basis tear secretion during first 2
days of life

15. • Conjunctiva in children is thicker and
tougher(probably due to greater height of
epithelial cells)
• Conjunctival sac is usually sterile at birth.

16. • Changes in cornea in first few year include
enlargement, flattening, thinning and increase
in transparency.
• Corneal diameter at birth: horizontal 9.8mm
average and vertical 10.4mm
• Investigations are recommended if corneal
diameter of <9mm or >11mm is found in new
born babies.
• Cornea is 0.96mm thick in center and becomes
0.52mm thicker by age 6 months.
• Peripheral thickness is 1.2mm.
• Corneal power 51.2 D ----43.5D

17. • Iris color changes and becomes permanent
during first 6 months.
• A newborn's pupil grows from approximately 2.2
mm to an adult length of 3.3 mm.
• Pupil is small, mean diameter is 3.6mm due to
constant state of sleep and poorly developed
dilator muscle.
• Abnormal pupil size in infants is <1.8mm and
>5.2mm.
• Pupillary response by 31 weeks of gestation is
positive.

18. • Angle is shallow and iris and ciliary
processes are inserted posteriorly.
• Mean IOP is 9.52 +- 2.66mm of Hg.

19. Lens
• Crystalline lens which averages 45 D during infancy,
loses about 20 D of power by the age 6 years.
• Refractive index of the lens also decreases.
• Lens thickness increases to a maximum at the
age of 10 weeks and then decreases.
• Eyes of children aged 1 – 2 years had significantly
thinner lenses than those of neonatal 1 – 4 days old.
• A thinning of the crystalline lens by 0.5 mm between
birth and the age of 13 years, with 60% of the effect
occurring before the age of 3 years.

20. • Macula is least developed at birth
• Macular pigmentation appears by 34 -35
weeks gestation.
• Foveal reflex is present by 37 weeks
gestation.

21. Retina
• Foveal region gets to be thinner ( 1000лm --- 700 лm )
by 4 yrs.
• Conesdensity/areaincreasesby age.
• Moreperipheral retinadevelopsfaster than foveal area.
• The retina contains mostly rod cells
• At 1 month postnatal
• Cone cells appear
• At 8 months postnatal
• Macula is mature

23. VISUAL SYSTEM
• the visual system – components from the eye
to neural circuits – develops largely after
birth, especially in the first few years of life. At
birth, visual structures are fully present yet
immature in their potentials.

24. Steps in Infant Vision
Development
• At birth, babies can't see as well as older
children or adults. Their eyes and visual
system aren't fully developed. But significant
improvement occurs during the first few
months of life.

25. At birth
• Poor eyesight
• Infant will blink in response to bright light or
touching eye
• Eyes are sometimes uncoordinated, may look
cross-eyed
• Able to stare at object if held 8 to 10 inches
away
• Initially fixes eyes on a face or light then
begins to follow a moving object

26. One Month
 The infant can follow a slowly moving black and white
target to midline; he/she will blink at a light flash, he
may also follow faces (usually with the eyes and head
both moving together).
 Acuity is still poor, and ocular movements may often
be uncoordinated.
 Newborns can only focus about eight to 12 inches from
their face.
 Looks at faces and pictures with contrasting black and
white images
 Can follow an object up to 90 degrees
 Watches parent closely
 Tears begin to form

27. Two Months
 For the first two months of life, an infant's eyes are not well
coordinated and may appear to wander or to be crossed.
This is usually normal. However, if an eye appears to turn in
or out constantly, an evaluation is warranted.
 Begins to be able to see an object as one image
 Brief fixation occurs, although ocular movements are still
uncoordinated. There may be attention to objects up to 6″
away.
 The infant follows vertical movements better than
horizontal, and is beginning to be aware of colors (primarily
red and yellow).

28. Three Months
Ocular movements are coordinated most of the
time; attraction is to both black and white and
colored targets.
The infant is capable of glancing at smaller
targets (as small as 1"), and is interested in
faces; visual attention and visual searching
begins.
The infant begins to associate visual stimuli and
an event (e.g., the bottle and feeding).
Babies should begin to follow moving objects
with their eyes and reach for things at around
three months of age.

29. Four Months
 "Hand regard" occurs (marked interest in the infant's own
hands).
 He/she reacts (usually smiles) to familiar faces.
 He/she is able to follow a visual target past midline and can
track horizontally, vertically, and in a circle.
 Can stare at a block
 Visual acuity may be in the 20/200 to 20/300 range.

30. Five Months
 The infant is able to look at an object in his/her ownThe infant is able to look at an object in his/her own
hands.hands.
 The infant is visually aware of the environment and canThe infant is visually aware of the environment and can
shift gaze from near to far easily .shift gaze from near to far easily .
 he/she can "study" objects visually at near point and canhe/she can "study" objects visually at near point and can
converge the eyes to do so; can fixate objects at 3 .″converge the eyes to do so; can fixate objects at 3 .″
 Eye-hand coordination (reaching) is usually achieved .Eye-hand coordination (reaching) is usually achieved .
 Depth perception is not developed 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.
 Although an 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.

31. Six MonthsSix Months
• Eye movements are coordinated and smooth; vision can be
used efficiently at both near point and at a distance.
• The child recognizes and differentiates faces at 6 and can″
reach for and grasp a visual target.
• Hand movements are monitored visually .
• He may be interested in watching falling objects, and usually
fixates on where the object disappears.

32. Between 6 and 9 Months
Acuity improves rapidly (to near normal).
He can explores visually (watches what is
going on around him/her).
He can transfer objects from hand to hand,
and may be interested in geometric patterns.

33. Between 9 and 12 Months
 He watch faces and try to imitate expressions.
 Search for hidden objects
 Can stare at small objects
 Visually alert to new people, objects and surroundings
 Differentiate between familiar and unfamiliar people
 Babies can now judge distances fairly well and throw things
with precision.

34. One year
• Both near and distant acuities are good.
• Can watch objects that are moving fast
• He can discriminate between simple
geometric forms (circle, triangle, square),
scribbles with a crayon, and is visually
interested in pictures.

35. Two years
• Myelination of the optic nerve is completed; all
optical skills are smooth and well coordinated.
• Visual acuity is normal.
• The child can imitate movements, match same
objects by single properties (color, shape), and can
point to specific pictures in a book.

36. Three years
• Retinal tissue is mature.
• He can do simple puzzles,
• He can draw a crude circle, and can
put 1" things into holes.

37. Preschool Vision:
2 to 5 Years of Age
• From ages 2 to 5, a child will be fine-tuning the visual
abilities gained during infancy and developing new
ones.
• This is also the time when parents need to be alert for
the presence of vision problems like crossed
eyes or lazy eye. These conditions often develop at this
age.
• In addition, parents should watch their child for
indication of any delays in development, which may
signal the presence of a vision problem. Difficulty with
recognition of colors, shapes, letters and numbers can
occur if there is a vision problem.

38. School-aged Vision:
6 to 18 Years of Age• Every child needs to have the following vision skills at this age:
• Visual acuity — the ability to see clearly in the distance for viewing the chalkboard, at an
intermediate distance for the computer, and up close for reading a book.
• Eye Focusing — the ability to quickly and accurately maintain clear vision as the distance
from objects change, such as when looking from the chalkboard to a paper on the desk and
back. Eye focusing allows the child to easily maintain clear vision over time like when reading
a book or writing a report.
• Eye tracking — the ability to keep the eyes on target when looking from one object to
another, moving the eyes along a printed page, or following a moving object like a thrown
ball.
• Eye teaming — the ability to coordinate and use both eyes together when moving the eyes
along a printed page, and to be able to judge distances and see depth for class work and
sports.
• Eye-hand coordination — the ability to use visual information to monitor and direct the
hands when drawing a picture or trying to hit a ball.
• Visual perception — the ability to organize images on a printed page into letters, words and
ideas and to understand and remember what is read.

39. Visual Acuity
• The vision of infants under one month of age
ranges from 20/800 to 20/200.
• By two months, visual acuity improves to
20/150.
• By four months, acuity improves by a factor
of 2 – calculated to be 20/60 vision.
• As the infant grows, the acuity reaches the
healthy adult standard of 20/20 at six months.
[5]

40. Development of Visual Acuity
• Visual acuity contrast sensitivity
• Birth ≈ 6/300 unknown
• 3 months 6/90 --- 6/60 ≈ 6/60
• 1 yr ≈ 6/24 ≈ 6/9
• 2 yrs ≈ 6/12 --- 6/9 ≈ 6/6
• 3 yrs ≈6/9 ---6/6 ≈ 6/6

41. Focusing Ability
• Most infants can focus accurately by two to
three months of age.

42. Binocular Vision
• Convergence:1 month after birth
• Conjugate fixation reflex: 5 to 6weeks of age
• Saccades: 4 months of age
• Conjugate movements of binocular vision: 6
months
• Fusional movements: 6 to 8 months

43. • Stereopsis development usually
parallels visual acuity.
• Appears at age 3.5 to 6 months
• Adult levels of stereopsis achieved by
the age of 6 months.

44. Field of Vision
• Infant’s field of vision
– At 2 months ~ peripheral vision is 15 degrees
lateral of central vision
– At 7 weeks ~ peripheral vision is 35 degrees
lateral of central vision

45. © 2007 McGraw-Hill Higher Education.
All rights reserved.
Tracking and Object Interception
40-52
weeks
Can track a 180 degree arc
5-6 yr Can track objects in horizontal
plane
8-9 yr Can track balls that travel in arc

46. Light Sensitivity
• At birth, infants have the greatest sensitivity to
intermediate wavelengths (yellow/green) and
less to short (blue/violet) or long (red/orange).

47. • Newborns can perceive few colors, but By 3-4
months newborns are able to see the full
range of colors (Kellman, 1998).
Color Sensitivity

48. • At 1 week, the infant can
discriminate the
desaturated red from
gray
• At 2 months, the infant
can discriminate the
desaturated blue from
gray

50. • Refractive errors by birth dependent on
relationship between axial length and
combined refractive power of cornea and
axial length.
• Usually new born are hypermetropes.
• Astigmatism is seen in 71% of infants.
• Gradual decrease in hyperopia up to age 7
then usually a myopic shift occurs till
childhood.