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Presentation on theme: "Eyes."— Presentation transcript:

1 Eyes

2 External 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

3 External Anatomy External Anatomy

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

7 Cornea – clear, covers & protects iris & pupil


9 Lacrimal apparatus – irrigates conjunctiva & cornea
3 parts Lacrimal gland, upper, outer corner of eye = tears Puncta= inner canthus, tear drainage Nasolacrimal duct= allows tears to drain from puncta to nasolacrimal sac. Tears then empty into the inferior meatus of the nose


11 Extraoccular muscles 6 muscles Attach eyeball to orbit
Straight and rotary movement Four straight muscles Superior rectus Inferior rectus Lateral rectus Medial rectus

12 Two slanting/ oblique muscles
Superior 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



16 Internal Anatomy The eye has 3 layers, the outer & inner layer can be viewed using opthalmascope Sclera (outer layer) tough, protective, white covering connects with the - Cornea – transparent, protects pupil & iris – helps focus light on retina

17 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 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


21 Visual 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.


23 Visual 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



26 Subjective data Vision difficulty Pain Strabismus, diplopia
Redness, swelling Watering, discharge Past history ocular problems Glaucoma

27 Glasses/ contacts Medications Vision loss- coping mechanisms Self–care behaviors

28 Objective data The Physical Exam
Preparation Position- sitting, head at eye level Equipment Snellen eye chart- visual acuity Handheld visual screener-near vision Opaque card Penlight Applicator stick Ophthalmoscope

29 Test visual acuity Snellen 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 /30 refer to opthalmologist or optometrist If unable to see largest letters, move to 10 feet – record as 10/200

30 Test 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 fields Confrontation 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 )


34 Inspect Extraoccular Muscle Function
Corneal light reflex Cover test Diagnostic positions test 6 Cardinal Positions of Gaze

35 Inspect Extraocular Muscle Function
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 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


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 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



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


46 Anterior Eyeball Structures
Cornea & lens Iris & pupil Size & shape Pupillary light reflex Accommodation

47 Cornea & Lens Shine light from side across cornea
Check smoothness, clarity Normally no opacities

48 Iris 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 Record the normal response to these tests as
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 (internal 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 lateral angle & 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.


56 Retinal background Light – dark red normally Note Lesions
Size, shape, color, distribution

57 Macula & Fovea Centralis
Last in Funduscopic exam 1 DD in size Darker than rest of fundus Foveal light reflex Exam last


59 Retinal 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 & Developmental Considerations
Review Abnormalities of the Eyes

61 3 most common causes of decreased visual functioning in the 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

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