Assessing Eyes Flashcards
the degree of detail the eye can discern in an image
visual acuity
the area an individual can see when looking straight ahead
visual fields
(nearsightedness)
myopia
(farsightedness)
hyperopia
(loss of elasticity of the lens and thus loss of ability to see close objects).
presbyopia
an uneven curvature of the cornea that prevents horizontal and vertical rays from focusing on the retina, is a common problem that may occur in conjunction with myopia and hyperopia.
Astigmatism
People with denominators of 40 or more on the Snellen chart with or without corrective lenses need to be referred to an
optometrist or ophthalmologist.
(inflammation of the bulbar and palpebral conjunctiva) may result from foreign bodies, chemicals, allergenic agents, bacteria, or viruses.
Redness, itching, tearing, and mucopurulent discharge occur. During sleep, the eyelids may become encrusted and matted together.
Conjunctivitis
(inflammation of the lacrimal sac) is manifested by tearing and a discharge from the nasolacrimal duct.
Dacryocystitis
___ (sty) is a redness, swelling, and tenderness of the hair follicle and glands that empty at the edge of the eyelids.
Hordeolum
(inflammation of the iris) may be caused by local or systemic infections and results in pain, tearing, and photophobia (sensitivity to light).
Iritis
are “black eyes” resulting from injury.
Contusions or hematomas
tend to occur in individuals over 65 years old although they may be present at any age. This opacity of the lens or its capsule, which blocks light rays, is frequently removed and replaced by a lens implant.
It may also occur in infants due to a malformation of the lens if the mother contracted rubella in the first trimester of pregnancy.
Cataracts
(a disturbance in the circulation of aqueous fluid, which causes an increase in intraocular pressure) is the most frequent cause of blindness in people over age 40 although it can occur at younger ages.
It can be controlled if diagnosed early.
Danger signs of it include blurred or foggy vision, loss of peripheral vision, difficulty focusing on close objects, difficulty adjusting to dark rooms, and seeing rain-bow-colored rings around lights.
Glaucoma
Upper eyelids that lie at or below the pupil margin are referred to as ___ and are usually associated with aging, edema from drug allergy or systemic disease (e.g., kidney disease), congenital lid muscle dysfunction, neuromuscular disease (e.g., myasthenia gravis), and third cranial nerve impairment. DROOPING UPPER EYELIDS
ptosis
Eversion, an outturning of the eyelid, is called __;
ectropion
inversion, an inturning of the lid, is called ___.
entropion
Pupils are normally black, are equal in size (about ___ in diameter), and have round, smooth borders.
3 to 7 mm
(enlarged pupils) may indicate injury or glaucoma, or result from certain drugs (e.g., atropine, cocaine, amphet-amines).
Mydriasis
(constricted pupils) may indicate an inflammation of the iris or result from such drugs as morphine or heroin and other narcotics, barbiturates, or pilo-carpine. It is also an age-related change in older adults.
Miosis
(unequal pupils) may result from a central nervous system disorder; however, slight variations may be normal.
Anisocoria
The eye transmits ____ to the brain for interpretation and, in doing so, functions as the organ of vision.
visual stimuli
The eyeball is located in the ___, a round, bony hollow formed by several different bones of the skull,
In here, a cushion of fat surrounds the eye.
eye orbit
are two movable structures composed of skin and two types of muscle: striated and smooth.
Their purpose is to protect the eye from foreign bodies and limit the amount of light entering the eye.
In addition, they serve to distribute tears that lubricate the surface of the eye
eyelids (upper and lower)
The ___ is larger, more mobile, and contains tarsal plates made up of connective tissue
upper eyelid
The eyelids join at two points:
the lateral (outer) canthus and medial (inner) canthus.
The medial canthus contains the __, two small openings that allow drainage of tears into the lacrimal system, and the caruncle, a small, fleshy mass that contains sebaceous glands.
puncta
The white space between open eyelids is called the
palpebral fissure
are projections of stiff hair curving outward along the margins of the eyelids that filter dust and dirt from air entering the eye.
Eyelashes
The ___ is a thin, transparent, continuous membrane that is divided into two portions: a palpebral and a bulbar portion.
conjunctiva
The ___ consists of glands and ducts that lubricate the eye
lacrimal apparatus
The ___, located in the upper outer corner of the orbital cavity just above the eye, produces tears.
Tears empty into the lacrimal canals and are then channeled into the nasolacrimal sac through the nasolacrimal duct. They drain into the nasal meatus.
lacrimal gland
The ___ are the six muscles attached to the outer surface of each eyeball. This associated nerves control six different directions of eye move-ment.
extraocular muscles
What are the six extraocular muscles
four rectus muscles (superior, inferior, lateral, and medial)
two oblique muscles (superior and inferior)
Innervation for these muscles is supplied by three cranial nerves: the oculomotor (III), trochlear (IV), and abducens (VI).
The external layer consists of the
sclera and cornea
The ___ is a dense, protective, white covering that physically supports the internal structures of the eye. It is continuous anteriorly with the transparent cornea (the “window of the eye”).
sclera
The ___ permits the entrance of light, which passes through the lens to the retina. It is well supplied with nerve endings, making it responsive to pain and touch.
cornea
The ___ 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
The __ is a circular disc of muscle containing pigments that determine eye color. The central aperture of the iris is called the ___. Muscles in the iris adjust to control the pupil’s size, which controls the amount of light entering the eye. The muscle fibers of the iris also decrease the size of the pupil to accommodate for near vision and dilate the pupil when far vision is needed.
The lens is a biconvex, transparent, avascular, encapsulated structure located immediately posterior to the iris. Sus-pensory ligaments attached to the ciliary body support the position of the lens. The lens functions to refract (bend) light rays onto the retina. Adjustments must be made in refraction depending on the distance of the object being viewed.
Refractive ability of the lens can be changed by a change in shape of the lens (which is controlled by the ciliary body).
The lens bulges to focus on close objects and flattens to focus on far objects.
The choroid layer contains the vascularity necessary to provide nourishment to the inner aspect of the eye and prevents light from reflecting internally. Anteriorly, it is continuous with the ciliary body and the iris
iris, pupil
Muscles in the iris adjust to control the pupil’s size, which controls ___
the amount of light entering the eye.
The muscle fibers of the iris also decrease the size of the pupil to ___
accommodate for near vision and dilate the pupil when far vision is needed.
The ___ is a biconvex, transparent, avascular, encapsulated structure located immediately posterior to the iris. Suspensory ligaments attached to the ciliary body support the position of the lens.
It functions to refract (bend) light rays onto the retina.
lens
The ___ contains the vascularity necessary to provide nourishment to the inner aspect of the eye and prevents light from reflecting internally. Anteriorly, it is continuous with the ciliary body and the iris.
choroid layer
It extends only to the ciliary body anteriorly.
It receives visual stimuli and sends it to the brain.
It consists of numerous layers of nerve cells, including the cells commonly, called rods and cones.
These specialized nerve cells are often referred to as “photoreceptors” because they are responsive to light.
Retina
The ___ are highly sensitive to light, regulate black-and-white vision, and function in dim light.
rods
The __ function in bright light and are sensitive to color.
cones
The ___ is a cream-colored, circular area located on the retina toward the medial or nasal side of the eye.
It is where the optic nerve enters the eyeball.
It can be seen with the use of an ophthalmoscope and is normally round or oval in shape, with distinct margins.
optic disc
A clear liquid substance produced by the ciliary body.
It helps cleanse and nourish the cornea and lens as well as maintain intraocular pressure (IOP).
It filters out of the eye from the posterior to the anterior chamber and then into the canal of Schlemm through a filtering site called the trabecular meshwork.
aqueous humor
Another chamber, the vitreous chamber, is located in the area behind the lens to the retina. It is the largest of the chambers and is filled with a ___ that is clear and gelatinous.
vitreous humor
refers to what a person sees with one eye. It can be divided into four quadrants: upper temporal, lower temporal, upper nasal, and lower nasal
visual field
The ___ are the main eye components that refract (bend) light rays on the retina.
cornea and lens
The ___ causes pupils to constrict immediately when exposed to bright light.
pupillary light reflex
is a functional reflex allowing the eyes to focus on near objects. This is accomplished through movement of the ciliary muscles, causing an increase in the curvature of the lens.
Accommodation
Eyes turned inward
Esotropia
Eye turned outward
Exotropia
Eye turned upward
Hypertropia
Eye turned downward
Hypotropia
The ___, also known as the corneal light reflex test, is a simple eye exam used to assess eye alignment, particularly for detecting strabismus (misalignment of the eyes), by observing the position of light reflected off the corneas
Hirschberg test
lipid deposits that appear as rings on the outer region of the cornea.
Arcus senilis
is an area of missing tissue in your eye
Coloboma
The ___ is a simple, at-home eye test used to monitor for changes in central vision, particularly those related to conditions like age-related macular degeneration (AMD), by detecting distortions, blurriness, or missing areas in the grid
Amsler grid
(DISTORTION) in amsler grid
METAMORPHOPSIA
(BLIND SPOT) in amsler grid
SCOTOMA
Test for visual field
• Temporal Field - 90 degrees
• Downward Field - 70 degrees
• Nasal Field - 60 degrees
• Upward Field - 50 degrees
A ___ is an eye chart used to measure visual acuity
Snellen chart
