ASSESSING EYES Flashcards
transmits visual stimuli to the brain for interpretation and, in
doing so, functions as the organ of vision.
EYES
EXTERNAL STRUCTURE OF THE EYE
Eyelids
Eyelashes
Conjunctiva
Lacrimal apparatus
Extraocular muscles
– the white space between open eyelids
Palpebral fissure
(upper and lower) are two movable structures composed of
skin and two types of muscle: striated and smooth
Eyelids
Medial canthus
– a small, fleshy mass that contains
sebaceous glands.
Caruncle
protect the eye from foreign bodies; limit the
amount of light entering the eye; serve to distribute tears
that lubricate the surface of the eye
Eyelids
The eyelids join at 2 points:
the lateral (outer) canthus and
medial (inner) canthus
Medial canthus
-2 small openings that allow
drainage of tears into the lacrimal system
Puncta
Conjunctiva is a thin, transparent, continuous membrane that is divided
into two portions:
a palpebral and a bulbar portion.
are projections of stiff hair curving outward along the
margins of the eyelids that filter dust and dirt from air entering the eye.
Eyelashes
is a thin, transparent, continuous membrane that is divided into two portions: a palpebral and a bulbar portion.
Conjunctiva
Conjunctiva
– lines the inside of the eyelids
Palpebral conjunctiva
consists of glands and ducts that lubricate the eye
Lacrimal apparatus
Conjunctiva
– covers most of the anterior eye,
merging with the cornea at the limbus.
Bulbar conjunctiva
located in the upper outer corner of the
orbital cavity just above the eye, produces tears.
Lacrimal gland –
are the six muscles attached to the outer surface of each eyeball. These muscles control six different directions of eye movement.
Extraocular muscles
Eyeball is composed of three separate coats or layers.
External layer
Sclera
Cornea
Middle layer contains both an anterior portion, which
includes the iris and the ciliary body, and a posterior
layer, which includes the choroid.
o Innermost layer- the retina,
dense, protective, white covering that
physically supports the internal structures of
the eye.
Sclera
permits the entrance of light, which passes
through the lens to the retina
Cornea
is a cream-colored, circular area
located on the retina toward the medial or
nasal side of the eye.
Optic disc
consists of muscle tissue that controls the thickness of the lens, which must be adapted to focus on objects near and far away.
Ciliary Body
circular disc of muscle containing pigments that determine
eye color
Iris
- central aperture of the iris
Pupil
a biconvex, transparent, avascular, encapsulated structure
located immediately posterior to the iris.
Lens
Refractive ability of the lens can be changed by a change
in shape of the lens (which is controlled by the
ciliary
body).
Lens Adjustments must be made in ____ depending on the
distance of the object being viewed.
refraction
contains the vascularity necessary to provide nourishment
to the inner aspect of the eye and prevents light from
reflecting internally
Choroid Layer
The lens____ to focus on close objects and _____ to
focus on far objects.
bulges
flattens
Retina consists of numerous layers of nerve cells, including the
cells commonly called
rods and cones
extends only to the ciliary body anteriorly
* It receives visual stimuli and sends it to the brain
* consists of numerous layers of nerve cells, including the
cells commonly called rods and cones
Retina
retinal depression located adjacent to the
optic disc in the temporal section of the fundus; this area is
surrounded by the macula, which appears darker than the
rest of the fundus
fovea centralis
refers to what a person sees with one
eye.
Visual Fields and Visual Pathways
are dark red and grow progressively narrower as they
extend out to the peripheral areas
* Arterioles carry oxygenated blood and appear brighter red
and narrower than the veins
Retinal Vessels
The visual field of each eye can be divided into
four quadrants:
upper temporal, lower temporal,
upper nasal, and lower nasal.
occurs as light rays strike the
retina, where they are transformed into nerve
impulses, conducted to the brain through the optic
nerve, and interpreted.
Visual perception
Pupillary light reflex causes pupils immediately to
constrict when exposed to bright light.
Visual Reflexes
Used to test distant visual acuity, consists of lines of different letters
stacked one above the other.
o Snellen Chart
Used if the client cannot read or has a
handicap that prevents verbal communication.
Configured just like the Snellen chart but the
characters on it are only Es, which face in all
directions.
E Chart
- Near vision is assessed in clients over
40 years of age by holding the pocket screener or newspaper print 14 inches from the
eye. Clients who have decreased accommodation to
view closer print will have to move the card or
newspaper further away to see it.
Jaeger Test
is a hand-held instrument that allows the examiner to
view the fundus of the eye by the projection of light
through a prism that bends the light 90 degrees.
Ophthalmoscope
(e.g., blind right
eye)
Unilateral blindness
(loss of vision
in both temporal fields)
- Bitemporal hemianopia
___ or
similar loss of vision (homonymous) in
quadrant of each field
Left superior quadrant anopia
Right visual field loss—___ or similar
loss of vision in half of each field
right
homonymous hemianopia
Normal in young children, the pupils will appear at
the inner canthus (due to the epicanthic fold)
Pseudostrabismus
(eye turns inward).
Esotropia
– drooping eye
Ptosis
(eye turns outward)
o Exotropia
- inwardly turned lower eyelid
Extropion
– generalized inflammation of the
conjunctiva
Conjunctivitis
– staphylococcal infection of the eyelid
Blepharitis
- protruding eyeballs and retracted eyelids
Exophthalmos -
- infected meibomian gland
Chalazion
- inflammation of the sclera
Diffuse episcleritis
ABNORMALITIES OF THE CORNEA
Corneal Scar
o appears grayish white, usually is due to an old injury
or inflammation
* Early pterygium
o thickening of the bulbar conjunctiva that extends
across the nasal side
ABNORMALITIES OF THE LENS
Nuclear Cataract
o appear gray when seen with a flashlight
o appear as a black spot against the red reflex when
seen through an ophthalmoscope
* Peripheral/Cataract
o look like gray spokes that point inward when seen
with a flashlight
o look like black spokes that point inward against the
red reflex when seen through an ophthalmoscope
