WEEK 11- EYES Flashcards
Explain how to assess central visual acuity (refer to CNII-optic) using the Snellen Chart.
Snellen chart
- see where you can read up till- thats your vision
- 20/20- good
- 20/70- bad
tests your CNII optic nerve.
Explain how to perform a diagnostic visions test (refer to CNIII-oculomotor, CNIV-trochlear & CNVI-abducens).
Diagnostic positions test
“6 cardinal positions”
Testing muscle weakness
Clockwise
Hold target at 30cm & ask client to hold head steady & follow with eyes
Normal findings
parallel tracking of eyes & no nystagmus
Describe normal findings for inspection of external ocular structures (exclude eversion of upper lid & lacrimal apparatus)
6 extraocular muscles
Binocular single-image visual system
“Conjugate movement”
Eye movement
CN III (oculomotor)
Superior, inferior & medial rectus
Inferior oblique
CN IV (trochlear)
Superior oblique
CN VI (abducens)
Lateral rectus muscle
Upper eye lids overlap the superior part of the iris
Skin is intact
No redness
No swelling
No discharge
No lesions
Sclera white ( dark skin can be grey blue or “muddy”
Eyeballs moist and glossy
Eyelashes evenly distributed
Eyeballs are aligned no protrusion or sunken appearance
Those of African descent may have slight protrusion beyond supraorbital edge
Conjunctive no redness noted
Dark skinned individuals- small brown macules on sclera / yellowish fatty deposits beneath eyelids
Inspect anterior eyeball structures –cornea, lens, iris & pupil.
Inspect anterior eyeball structures
Cornea & lens
Iris
Pupil & pupillary light reflex
Note pupil size, shape & equality before & after introduction of light source
Ask person to gaze into distance (darken room)
Advance light in from side on both eyes
Direct Light Reflex & Consensual light reflex
Describe & assess: Confrontation Test
The examiner holds a target object, such as a finger or small object, at various positions within the patient’s peripheral visual field while maintaining central fixation.
Starting from the central position (directly in front of the patient), the examiner systematically moves the target object in different directions (up, down, right, left, and diagonally) within the patient’s peripheral visual field.
The examiner observes the patient’s responses and notes any indications of visual perception or awareness of the target object in each directio
Describe & identify abnormal findings of ptosis, diplopia, strabismus & nystagmus, & glaucoma.
ptosis- dropping of upper eyelid
diplopia- 2 images of 1 single object; double vision
strabismus- cross eye
nystagmus- rapid eye movement back and forth
glaucoma- damage to the optic nerve, blindness if left untreated.
Describe developmental considerations over the lifespan
neonates
- trouble fixating on things until 3-4 months
- far sighted
aging adult
- presbyopia
- cataracts
- glaucoma
- macular degeneration
Identify health promotion strategies.
- eat healthy
- exercise
- lower blood pressure- if diabetic get screened for eyes
- eye exams
Identify equipment needed for physical examination & safe infection prevention & control practices.
Snellen eye chart
Handheld visual screener
Opaque card or occluder
Penlight (some come with a pupil gauge to measure pupil size)
Applicator stick
Ophthalmoscope
Presbyopia
decrease in lens ability to change shape to accommodate for near vision
Amblyopia
lazy eye
Diplopia
double vision
Myopia
near sightedness
Hyperopia
far sightedness
external features- eye
Bony orbital cavity
Upper & lower eyelids & palpebral fissure
Sclera
Iris
Limbus
Pupil
Medial and lateral canthus
Conjunctiva
Cornea
lacrimal apparatus
irrigation to conjunctiva, and cornea
- lacrimal gland secretes tears (drains into nasolacrimal duct)
- older people
extraocular muscles (3)
CNIII- oculomotor
CNIV- trochlear
CNVI- abducens
internal anatomy of eye
- outer layer
- sclera
cornea- refracting light
corneal reflex- CNV AND CNVII- trigemial, facial - middle layer
- controls the amount of light that is admitted into the retina through iris and pupil - retina
visual receptive layer
- light waves transmitted into nerve impulses
light response
Refraction of Light Rays
All objects reflect light
Light rays are refracted into the eye
Strike retina
Retina transforms light stimulus into nerve impulses through the optic nerve into the visual cortex
Right side of brain looks at left side of the world
health history questions
Vision difficulty
Pain
Strabismus (crossed eyes), diplopia (double images)
Redness, swelling
Watering, discharge
History of ocular problems
Glaucoma
Glasses or contact lenses
Self-care behaviors
Medications
Coping with vision loss
objective data- physical exam
Central visual acuity
Snellen eye chart
(tests CN II Optic nerve)
Normal visual acuity is 20/20
What does 20/70 mean?
What does 20/40 – mean?
NEAR VISION
40 yrs + or people who report difficulty reading
Use handheld screener
Hold card in good light – 14 inches from eyes
Test each eye separately
Normal = 14/14
Use magazine or newspaper if screener unavailable
EXTERNAL OCULAR STRUCTURES
Inspect external ocular structures
General
Eyebrows, eyelids & lashes
Eyeballs
Conjunctiva & sclera
CONJUNCTIVITS
What are the characteristics of conjunctivitis that the nurse should assess?
Conjunctivitis, also known as pink eye, is an inflammation of the conjunctiva, the thin, clear tissue that covers the white part of the eye and lines the inside of the eyelid.
SUBCONJUCTIVAL HEMMORAGE
What are the characteristics of subconjunctival hemorrhage?
A subconjunctival hemorrhage is a common and usually benign condition characterized by bleeding underneath the conjunctiva, the clear tissue that covers the white part (sclera) of the eye.
What are the characteristics of cataracts?
Cataracts are a common age-related eye condition characterized by clouding of the natural lens inside the eye, leading to progressive vision impairment.
What are the characteristics of Exophthalmos and how does it differ from Ptosis?
Exophthalmos refers to the protrusion or bulging of one or both eyeballs from their normal position within the eye sockets (orbits).
Ptosis refers to drooping or sagging of the upper eyelid, causing it to cover part of the eye or reduce the visible area of the iris and pupil.
What are the characteristics of the eyes of those who are elderly?
- macular degeneration
- presbyopia
- cataracts
pupil size decreases. The lens loses elasticity,
becoming hard and glasslike, which decreases the lens’s ability to
change shape to accommodate for near vision; this condition is
termed presbyopia
ANTERIOR EYEBALL STRUCTURES
Test for Accommodation
Adaptation of eye for near vision
Increasing curvature of the lens
Assessment:
Ask person to focus on distant object
Place finger 8cm from nose
Ask person to shift gaze to your finger
Pupillary constriction & convergence of the axis
normal pupils
PERRLA
Pupils Equal, Round, React to Light and Accommodation
COVER TEST
Test checks for alignment of the eyes
This test assess if eyes are working well parallel
Ask person to cover one eye and look directly at you- Normal response for both eyes is to gaze ahead
Ask person to uncover eye and observe for any movements of the eye- for those individuals with muscle weakness you will note the eye jumping every so slightly to be aligned with the other eye
tests
Cover test
Confrontation Test
Corneal Light Reflex
pupillary light reflex
The pupillary light reflex is the normal constriction of the pupils
when bright light shines on the retina
accommodation
Accommodation is adaptation of the eye for near vision. It is
accomplished by increasing the curvature of the lens through
movement of the ciliary muscles. Although the lens cannot be
observed directly, the components of accommodation that can be
observed are convergence (motion toward) of the axes of the
eyeballs and pupillary constriction
full eye exam
- Test visual acuity:
Snellen eye chart
Near vision (in patients older than 40 years of age or
those having difficulty reading) - Test visual fields: confrontation test
- Inspect extraocular muscle function:
Corneal light reflex (Hirschberg’s test)
Cover–uncover test
Diagnostic positions test - Inspect external eye structures:
General
Eyebrows
Eyelids and lashes
Eyeball alignment
Conjunctiva and sclera
Lacrimal apparatus - Inspect anterior eyeball structures:
Cornea and lens
Iris and pupil
Size, shape, and equality
Pupillary light reflex
Accommodation - Inspect the ocular fundus:
Optic disc (colour, shape, margins, cup–disc ratio)
Retinal vessels (number, colour, artery–vein ratio,
calibre, arteriovenous crossings, tortuosity, pulsations)
General background (colour, integrity)
Macula - Engage in teaching and health promotion
