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Eye Sensory,Disorder
Eye sensory and disorders
Question | Answer |
---|---|
Accommodation | The process by which the eye increases optical power to maintain a clear image (focus) on an object as it draws near the eye. |
Astigmatism | Irregularities in the curvature of the cornea and lens. Light rays are imperfectly focused on the retina. |
Binocular vision | The ability to maintain visual focus on an object with both eyes, creating a single visual image |
Blepharitis | Inflammation of the eyelid, caused by an infection or by dermatitis. |
Cataract | Clouding of the lens of the eye that impairs vision. |
Chalazion | Painless cyst or nodule of the eyelid. |
Conjunctivitis | Inflammation of the conjunctivitis. AKA Pink eye. |
Diplopia | Double vision and pain with eye movement. |
Enucleation | The surgical removal of any intact organ, such as an eye. Enucleation is only done under drastic circumstances such as to remove a malignant tumor in the eye or to relieve intolerable pain in a blind eye. Following enucleation, an artificial eye (ocular p |
Glaucoma | Increased intraocular pressure and gradual loss of vision. It is a silent thief of vision. |
Hordeolum | A localized, purulent, inflammatory staphylococcal infection of one or more sebaceous glands of the eyelids; also called stye. |
Hyperopia | Farsightedness caused by an abnormally short eyeball. |
Keratitis | Inflammation of the cornea, usually caused by infection, lack of tears, or trauma. |
Miotic | Drugs that constrict the pupil & contract the ciliary muscle. This stretches and opens the trabecular meshwork, promoting aqueous humor drainage & reducing intraocular pressure. |
Mydriatic | A drug that causes the pupil of the eye to dilate; used to aid eye examinations |
Myopia | Nearsightedness. The light rays are focusing in front of the retina. |
Ophthalmologist | Physician who specializes in the medical & surgical treatment eye disorders. |
Optician | Makes eye glasses or lens. |
Optometrist | Does vision testing, prescribes & fits lenses. Not a physician. |
Presbyopia | Impaired accommodation of the lens caused by aging. |
Optometrist | Does vision testing, prescribes & fits lenses. Not a physician. |
Presbyopia | Impaired accommodation of the lens caused by aging. Elasticity is lost. |
Ptosis | eyelid drooping |
Ptosis | eyelid dropping |
Refraction | Refraction of light (bending of light rays) |
Strabismus | Cross eye. One or both of the eyes may turn in, out, up or down |
Uveitis | Inflammation of the middle vascular layer of the eye. |
Tonometer | Measurer the intraocular pressure. Intraocular pressure is measured using a Schiotz tonometer or other tonometry instrument. |
Snellen Chart | Eye chart to measure visual acuity. |
Eyeball - Measurement and location | Measures 2.5 cm (1 inch) and sits in bony structure called the orbit. |
Eyeball lining | Muscle, connective & adipose tissue |
Orbit - Measurement & Surrounding | Approx. 4 cm high, wide, and deep. Surrounded by ethmoid, frontal & maxillary sinuses |
Eyelid - Description & glands contain within | Thin elastic skin covering muscles. Protects the anterior portion of the eye. Contains sebaceous, sweat, accessory lacrimal glands. Lid margins contain meibomian glands. |
Eye muscles are innervated by which cranial nerves? | Cranial nerves III, IV, VI innervate the eye muscles. |
Blinking washes what with tears? | Blinking washes the cornea & conjunctiva with tears |
What forms tears? | Lacrimal gland & accessory lacrimal glands. |
Conjunctiva | Mucous membrane that provides a barrier to the external environment & nourishes the eye. |
Iris | Colored portion of eye, surrounds pupil |
Bright light effect on eye | Constrict - Circular muscles contract and decrease the size of the pupil. |
Dim light effect on eye | Dilate - The radial muscles contract and increase the size of the pupil. |
What controls the constriction & dialation of the pupil? | Iris |
Uvea - Vascular tunic | Middle layer of eye. Nourishes eye, consists of iris, ciliary body, and thr choroids. |
Sharpest, keanist vision comes from what part of the eye? | Fovea (center of the macula) |
Opia | Vision |
My = Myo = ? | Muscle |
Vitamins for eye health | Vitamins A & D |
Photopobia | Eye sensitivity to light |
Sclera | White of eye. Gives shape to eyeball. |
Cornea | Window of the eye, main refracting surface os the eye. |
Choroid | Thin dark membrane that line internal surface of sclera. Absorbs light rays so they are not scattered off the inner layer of the eye. |
Lens | Colorless, almost completely transparent, biconvex structure held in position by zonular fibers. Avascular. Enables focusing for near vision and refocusing for distance vision. Suspended behind the iris. |
Vitreous Humor | Clear, gelatinous substance, composed mostly of water and encapusulated by a hyaloid membrane. |
Retina | Has 10 microscopic layers, consists of we tissue paper, called neural tissue, an extension of the optic nerve. |
Visual Pathway | Made up of retina, optic nerve (cranial nerve II), optic chiasm, optic tracks, lateral geniculate bodies, optic radiations, and the visual cortex area of the brain. Also an extension of the central nervous system. |
Physiology of vision | Before light reaches the rods and cones for image formation, it passes through the cornea, aqueous humor, pupil, lens, and vitreous humor. For vision to occur, light reaching the rods and cones must form an image on the retina. This result in nerve impuls |
Constriction of pupil | Narrowing diameter, simultaneously occurs with accomodation. Prevents light rays from entering through the periphery of the lens. |
Convergence | Both eyes foucs on a single object. Movement of the two eyeballs toward the nose. Coordinated action of the extrinsic eye muscles. |
Inverted images | Images are focused upside down on the retina. |
Light impulse is converted to... | nerve impulses |
Assessing the eye | Ocular hx, chief complaint or concern, visual acuity using snellen chart, external eye exam, condition of eyelashes & eyebrows, assess for scaling or crusting, sclera should be white, assess conjunctiva for drainage, check pupillary response, check extrao |
Ophthalmoscopy | Hand held, used to visualize the cornea, lens, & retina. Room should be darkened and give patient a target to gaze on. |
Slit-lamp examination | Binocular microscope mounted on table used to examine the eye with magnification of 10-40 times. |
Ultrasonography | Probe placed agains the eye aims the beam of sound. High frequency sound waves emitted are bounced back from the lesion and displays the sound waves on a special screen. Used to identify orbital tumors, retinal detachment and changes in tissue composition |
Fluorescein Angiography | Used for diagnosis of abnormalities of blood vessels, evaluates macular edema, macular capillary nonperfusion and neovascularization in age related macular degeneration. |
Gonioscopy | Visualizes the angle of the anterior chamber to ID abnormalties in appearance and measurements. |
Aqueous humor is produced by.. | ciliary body in the posterior chamber |
Helps maintain intraocular pressure (IOP) | Aqueous humor. Normal IOP is 10-21 mm/hg |
Uveitis | Inflammation of vascular layer. Severe pain, photophobia, blurred vision, constricted pupil, red limbus (around the iris). |
Iritis | Inflammation of iris. Severe pain, photophobia, blurred vision, constricted pupil, red limbus (around the iris). |
Medications used for infectious and inflammatory eye disorders | Topical anti-infectives, antihistamines, corticosteroids, mydriatics. |
Corneal abrasion | scratch of the cornea, can be caused by contact lenses, eyelashes, small foreign bodies, fingernails. |
Burn to the eyes can be caused by chemical or thermal burns, symptoms include | swollen eyelids, red edematous conjuctiva, cloudy cornea. |
Leading cause of blindness amoung children & young adults, especially male trauma victims | Ocular trauma |
OU | Both eyes |
OD | Right eye |
OS | Left eye |