2. External AnatomyExternal Anatomy
Sensory Organ for vision
-Situated in bony, orbital cavity for
protection
– Eyelids= shades that add protection form
injury, strong light , dust
– Eyelashes= hairs to filter dust & dirt
4. Limbus – border b/t the cornea & sclera
Palpebral fissures – elliptical open space b/t
lids
Canthus- corners of the eye where the lids
meet, inner & outer
Caruncle – sm. Fleshy mass containing
sebaceous glands at inner canthus
5. Within the upper eyelid
– Tarsal plates, connective tissue gives upper
lid shape
– Meibomian glands, in the plates, lubricate the
lids, stops overflow of tears, airtight seal
when lids closed
6. Exposed part of the eye
– Conjunctiva, folded envelope b/t eyelids &
eyeball
thin mucous membrane, transparent protective
covering of the exposed part of the eye.
Palpebral conjunctiva lines the lids, is clear but has
sm .bld. Vessels
Bulbar conjunctiva is over eyeball, white sclera
show through, merges at limbus with cornea
9. Lacrimal apparatus – irrigates conjunctiva
& cornea
– 3 parts
A. Lacrimal gland, upper, outer corner of eye = tears
B. Puncta= inner canthus, tear drainage
C. Nasolacrimal duct= allows tears to drain from
puncta to nasolacrimal sac. Tears then empty into
the inferior meatus of the nose
10.
11. Extraoccular musclesExtraoccular muscles
6 muscles
– Attach eyeball to orbit
– Straight and rotary movement
– Four straight muscles
1. Superior rectus
2. Inferior rectus
3. Lateral rectus
4. Medial rectus
12. Two slanting/ oblique muscles
5. Superior
6. Inferior
Humans have a Binocular, single – image
visual system – Eyes normally move as a
pair
13. • Eye movement stimulated by Cranial
Nerves
• III Oculomotor
• IV Trochlear
• VI Abducens
14.
15.
16. Internal AnatomyInternal Anatomy
The eye has 3 layers, the outer & inner
layer can be viewed using opthalmascope
1. Sclera (outer layer) tough, protective,
white covering connects with the -
Cornea – transparent, protects pupil &
iris – helps focus light on retina
17. 2. Middle layer
Choroid – dark pigmentation to prevent
internal light reflection, supplies bld. to retina
Pupil – PERRLA
Lens – biconvex disc, transparent, thickness
controlled by ciliary body, bulges = near;
flattens = distant
Anterior chamber – posterior to cornea,
anterior to iris & lens, has aqueous humor
supplies nutrients & drains wastes
18. 3. Inner layer – Retina – visual receptive
layer – light waves changed to nerve
impulses
Retinal structures
Optic disc – retinal fibers meet & form optic
nerve, nasal side of retina, creamy yellow orange
to pink, round or oval shape, physiologic cup
inside the disc for bld.vessels to enter & exit
Retina vessels – paired arteries & veins
19. Macula – temporal side of fundus, darker pigmented
region, surround the fovea centralis
Fovea Centralis- area of sharpest & keenest vision,
Very sensitive to light
20.
21. Visual Pathways & FieldsVisual Pathways & Fields
Objects reflect light
Rays refracted by cornea, aqueous humor, lens,
vitreous body and onto retina.
Light stimulus is changed to nerve impulses, travel
thru optic nerve to visual cortex in occipital lobe
Image on retina is upside down & reversed. At the
optic chiasm retinal fibers cross over. Right side
of brain looks at left side of world.
22.
23. Visual reflexesVisual reflexes
Pupillary light reflex – bright light = constriction
– Direct light reflex
– Consensual light reflex
Fixation – ability to track an object & keep image
on the fovea, can be impaired by drugs, alcohol,
fatigue & inattention
Accomodation – for near vision = pupil
constriction & convergence of eyes
24.
25.
26. Subjective dataSubjective data
Vision difficulty
Pain
Strabismus, diplopia
Redness, swelling
Watering, discharge
Past history ocular problems
Glaucoma
29. Test visual acuityTest visual acuity
Snellen eye chartSnellen eye chart
Stand 20 ft. from chart
Glasses / contacts (Document )
Remove eye wear, retest
Normal visual acuity is 20/20 – top # is distance
person is standing from the chart
Vision 20/30 refer to opthalmologist or
optometrist
If unable to see largest letters, move to 10 feet –
record as 10/200
30. Test for near visionTest for near vision
Vision screener
People > 40yrs or difficulty reading
Test each eye with glasses
Hold card 14in. from eyes
Normal result 14 / 14
Test using any available reading material if
no card available
31. Presbyopia is a normal physiological
change in near vision occurs with aging =
note if the person moves the card farther
away
32. Test visual fieldsTest visual fields
Confrontation testConfrontation test
Compares peripheral vision with a tester
who has normal peripheral vision
2 ft. apart, eye level
Tester & client cover opposite eyes
Tester advances finger in the periphery
– Superiorly ( 50 degrees )
– Inferiorly ( 70 degrees )
– Temporally ( 90 degrees )
33.
34. Inspect Extraoccular MuscleInspect Extraoccular Muscle
FunctionFunction
Corneal light reflex
Cover test
Diagnostic positions test
– 6 Cardinal Positions of Gaze
35. Inspect Extraocular MuscleInspect Extraocular Muscle
FunctionFunction
Corneal Light Reflex ( The Hirschberg
Test) assesses parallel eye alignment
– Shine light toward person’s eyes
– Tell to stare directly ahead
– Hold light 12 in. away
– Light should reflect on both corneas in same
spot
36. Cover Test- detects deviated alignment
– Stare straight at examiner’s nose
– Cover 1 eye of the person being examined with opaque
card
– Normally the uncovered eye should maintain a steady,
fixed gaze
– Covered eye- should stare straight ahead when covered
& then uncovered. If muscle weakness exists the
covered eye will relax and then jump to fixed position
when uncovered..
37. Diagnostic Positions TestDiagnostic Positions Test
6 cardinal positions of gaze –
– Determines muscle weakness during movement
– Person must hold head steady
– Follow movement of object (examiner’s finger, pen etc)
only with eyes
– Hold object 12 in. from person
– Move thru each position, clockwise, hold , then back to
center
– Normal response= parallel tracking with both eyes
38.
39. During this test be aware of Nystagmus-fine
jerky movement seen around the iris
Mild nystagmus in extreme lateral gaze is
normal but not normal in any other position
40. Inspect External StructuresInspect External Structures
General – movement & facial expression
(squinting?)
Eyebrows – 2(bilateral), symmetrical (look the
same; move the same)
Eyelids & Lashes – present, approximate when
closed, no redness, swelling, discharge, lesions?
Eyeballs- alignment, ? Protrusion? Sunken?
Conjunctiva & Sclera – moist, glossy, clear, white
sclera
41. Eversion of the upper eyelid FYI – we will
not do this examine in lab see pg. 312 for
technique – usually done for complaint of
eye pain due to foreign body
42.
43.
44. Lacrimal Apparatus
– Person looks down
– Using thumbs, slide outer part of upper lid
along bony orbit
– Note redness or swelling
– Press index finger against lacrimal sac at inner
canthus
– Normal response is slight eversion of lower lid,
no tearing or discharge
47. Cornea & LensCornea & Lens
Shine light from side across cornea
Check smoothness, clarity
Normally no opacities
48. Iris and PupilIris and Pupil
Iris = flat, round, regular, even color
bilaterally.
Pupils = PERRLA
– Resting size norm = 3-5mm
– 5% population have pupils of 2 diff. Sizes
called Anisocoria
49. Pupillary Light Reflex
– Darken room
– Person gazes straight ahead
– Advance light from the side
Direct light reflex
Consensual light reflex
– Measure pupil size before & after light reflex
– Measurement R3/1 L3/1 =both pupils measure
3mm in resting state & 1mm with light
50. Accomodation
– focus on distant object -dilatation of pupils
– Shift gaze to near object – pupils constrict &
converge
Record the normal response to these tests as
PERRLA = Pupils Equal, Round, React
to Light and Accomodation
51. Ocular Fundus (internalOcular Fundus (internal
surface of retina)surface of retina)
Use Opthalmoscope- try keeping both eyes
open- practice looking at a ring on your
finger. Become familiar with the instrument
before you examine your partner’s eyes
52. Diopter of opthalmoscope
– Black numbers = +diopter, focus on near
objects
– Red numbers = - diopter, focus on further
objects
Use ophthalmoscope in darkened room =
dilates pupils
53. Remove examiner’s and person’s
eyeglasses but contact lenses may be left in.
Select lg. White aperture light
Person should focus on a distant object and
try & remain still
Examiner hold ophthalmoscope in Right
hand to right eye to eamine person’s right
eye
54. Begin 10in away at 150
lateralangle &
advance
Keep sight of red reflex
Adjust lens to +6 as you advance till your
foreheads almost touch. Adjust diopter to
focus.
– Normal vision set at 0. Nearsighted use red #s.
Farsighted use black.
57. Macula & Fovea CentralisMacula & Fovea Centralis
Last in Funduscopic exam
– 1 DD in size
– Darker than rest of fundus
– Foveal light reflex
– Exam last
58.
59. Retinal VesselsRetinal Vessels
Arteries Veins
COLOR Light red Dark red
SIZE Smaller 2/3 to
4/5 diam. Of
veins
Larger
LIGHT
REFLEX
Bright Inconspicuous
absent
60. Read Aging & DevelopmentalRead Aging & Developmental
ConsiderationsConsiderations
Review Abnormalities of the Eyes
61. 3 most common causes of3 most common causes of
decreased visual functioning indecreased visual functioning in
the older adultthe older adult
Cataract (lens opacity)
Glaucoma (increased ocular pressure) = loss
of peripheral vision
Macular degeneration (breakdown of cells
in the macula lutea) = loss of central vision