Eyes Flashcards
What is the conjunctiva?
Thin membrane that keeps the outer eye and inner portion of the eyelids moist
What is ptosis?
When the upper eyelid droops down
What is the palpebral fissure?
Opening between the eyelids
Which muscles are responsible for up/down and right/left movement of the eye?
4 rectus muscles
Which muscles are responsible upper outer and lower inner movement of the eye?
2 oblique muscles
What is the function of the cornea?
To refract light
What is the pathway of light through the eye?
Cornea -> pupil -> lenses -> retina
What are rods responsible for?
Peripheral vision, dim light
Located all over the eye
What are cons responsible for?
Color, acuity, central vision
Clustered together in the center
What is an astigmatism?
Abnormality in sight
What is glaucoma?
When there’s a build up of pressure to the back of the eye
What is the pathway of aqueous humor?
Ciliary body produces -> posterior chamber -> pupil -> anterior chamber
What are crystalline lenses made of?
Protein
What is a cataract?
When the crystalline lens breaks down and becomes cloudy
What is macular degeneration?
When the macular region breaks down
Results in trouble seeing colors/vision
What is the sclera?
White of the eye
What does the sclera do?
Provide protection, structure
Optic nerve attached to this at the back of the eye
What is the cornea?
Continuous with sclera, transparent dome shaped window that cover the iris, pupil, and anterior chamber
What does the cornea do?
Provides most of the eyes optical power
What is aqueous humor?
Fluid produced by ciliary body that flows from posterior chamber through pupil to anterior chamber
What does aqueous humor do?
Controls pressure inside eye
What is the iris?
Circular, contractile muscular disc containing pigmented cells
What does the iris do?
Regulates the light levels inside eye
What is the pupil?
Center of the iris
Tiny sphincter muscles constrict pupil to light and tiny dilator muscles dilates eye in dim light
What is the purpose of the lens?
Focus light on the retina
Able to change shape and to adjust to close and distant vision (accommodation)
What is the retina?
Sensory network that lines the back of the eye
What does the retina do?
Transforms light impulses to electrical impulses
Impulses travel via optic nerve to cerebral cortex
Here they are transformed into images.
Arteries vs veins behind the eye
Arteries: Light red Smaller diameter (2/3 less than vein) Light Reflex: Bright Veins: Dark red Size: larger Light reflex: less bright or absent
What is a tonometer?
Instrument used to measure intraocular pressure
What occurs in the eye exam?
ROS Inspection of external structures Measurement of visual acuity Determination of visual fields Evaluation of EOM Estimation of Intraocular pressure.** Exploration of Ocular Fundus.**
What is included in the ROS?
Onset of problem gradual or sudden? Problem seeing close work or distance? Pain or headaches? Last eye exam? Glasses or contact lens? Changes in vision?
What to inspect during an external eye exam?
Eyelids: Blinking Lesions Superficial vascularity Edema. Ptosis Eversion, inversion of lids Enophthalmos Exophthalmos Corneal drying Palpate for ocular tension. Lacrimal apparatus Eyebrows
What is Exophthalmos?
Bulging eyes
What can cause Exophthalmos?
Graves disease, hyperthyroidism
What is Enophthalmos
Sunken eyes
What can cause Enophthalmos?
Dehydration/malnutrition
What is the part of the lacrimal apparatus that’s visible from the outside?
Puncta
What should you examine for the conjunctiva and sclera?
Palpebral conjunctiva lining the lids and bulbar conjunctiva covering sclera. Color Vascular patterns Nodules Swelling. Conjunctivitis
What is arcus senilis?
Gray ring around the iris
What is arcus senilis indicative of?
High cholesterol
What is presbyopia?
Far-sightedness
What is myopia?
Near-sightedness
What is hyperopia?
Far-sightedness
What tends to occur first: near-sightedness or far-sightedness?
Far-sightedness
What is a visual field?
The entire area seen by an eye when its gaze is fixed on a central point
What could lidlag indicate?
Problem with CN III or CN VII
What is convergence?
Putting finger far from eye and have pt tell you when it gets blurry as you slowly move closer to the eye
What is strabismus?
Eyes sort of look down because extraocular muscles are not strong enough
What is fundoscopy?
Seeing through pupil and into back of the eye for vessels and optic disc/nerve
What is used to check the back of the eye?
An ophthalmoscope
What is anisocoria?
Slight inequality in size of the pupils
What is miosis?
Constriction of pupils
What is mydriasis?
Dilation of pupils
