The following are health and medical definitions of terms that appear in the Eye Care article.
Abrasion: An abrasion or "excoriation" is a wearing away of the upper layer of skin as a result of applied friction force. In dentistry an "abrasion" is the wearing away of the tooth substance.
Acute: Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care. See the entire definition of Acute
Acute angle-closure glaucoma: Increased pressure in the front chamber (anterior chamber) of the eye due to sudden (acute) blockage of the normal circulation of fluid within the eye. The block takes place at the angle of the anterior chamber formed by its junction of the cornea with the iris. This angle can be seen by simply looking at someone's eye from the side. Angle-closure glaucoma tends to affect people born with a narrow angle. People of Asian and Eskimo ancestry are at higher risk of developing it. Age and family history are risk factors. It occurs in older women more often than others. See the entire definition of Acute angle-closure glaucoma
Aging: The process of becoming older, a process that is genetically determined and environmentally modulated. See the entire definition of Aging
Allergy: A misguided reaction to foreign substances by the immune system, the body system of defense against foreign invaders, particularly pathogens (the agents of infection). The allergic reaction is misguided in that these foreign substances are usually harmless. The substances that trigger allergy are called allergen. Examples include pollens, dust mite, molds, danders, and certain foods. People prone to allergies are said to be allergic or atopic. See the entire definition of Allergy
Anatomy: The study of form. Gross anatomy involves structures that can be seen with the naked eye. It is as opposed to microscopic anatomy (or histology) which involves structures seen under the microscope. Traditionally, both gross and microscopic anatomy have been studied in the first year of medical school in the U.S. The most celebrated textbook of anatomy in the English-speaking world is Gray's Anatomy, still a useful reference book. The word "anatomy" comes from the Greek ana- meaning up or through + tome meaning a cutting. Anatomy was once a "cutting up" because the structure of the body was originally learned through dissecting it, cutting it up. The abbreviation for anatomy is anat.
Angle-closure glaucoma: This condition can be acute or chronic. It consists of increased pressure in the front chamber (anterior chamber) of the eye due to sudden (acute) or slowly progressive (chronic) blockage of the normal circulation of fluid within the eye. The block takes place at the angle of the anterior chamber formed by its junction of the cornea with the iris. This angle can be seen by simply looking at someone's eye from the side. Angle-closure glaucoma tends to affect people born with a narrow angle. People of Asian and Eskimo ancestry are at higher risk of developing it. Age and family history are risk factors. It occurs in older women more often than others. When the pupil of the eye is wide open (dilated), the iris is retracted and thickened and it block the canal of Schlemm, a key component of the drainage pathway for fluid within the eye. Blocking the drainage canal of Schlemm sends the pressure within the eye up. With acute angle-closure glaucoma, there is an abrupt increase in intraocular pressure (IOP) due to the buildup of aqueous (fluid) in the eye. The high pressure can damage the optic nerve (the nerve to the eye) and lead to blindness. The elevated pressure is best detected before the appearance of symptoms. That is why when the eyes are dilated in a doctor's office for a refraction, eye pressures are checked. When symptoms of acute angle glaucoma do develop, they include severe eye and facial pain, nausea and vomiting, decreased vision, blurred vision and seeing haloes around light. The eye in a far advanced case of angle closure glaucoma appears red with a steamy (clouded) cornea and a fixed (nonreactive) dilated pupil. Acute angle-closure glaucoma is an emergency because optic nerve damage and vision loss can occur within hours of the onset of the problem. Administering medications to lower the pressure within the eye is done first. In the past, a piece of the iris was then surgically removed in a procedure called an iridectomy to make a hole in the iris and create a channel (other than the canal of Sclemm) to permit the free flow of fluid. Today, a comparable procedure can be done by laser to burn a small hole in the iris to keep the intraocular pressure within normal limits. This condition can be chronic (progressing slowly or occurring persistently) or acute (occurring suddenly). Chronic angle-closure glaucoma, like the more common type of glaucoma (open-angle glaucoma), may cause vision damage without symptoms.
Anterior: The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum). See the entire definition of Anterior
Anterior chamber: The space in the eye that is behind the cornea and in front of the iris. See the entire definition of Anterior chamber
Antidepressants: Anything, and especially a drug, used to prevent or treat depression. See the entire definition of Antidepressants
Antihistamines: Drugs that combat the histamine released during an allergic reaction by blocking the action of the histamine on the tissue. Antihistamines do not stop the formation of histamine nor do they stop the conflict between the IgE and antigen. Therefore, antihistamines do not stop the allergic reaction but protect tissues from some of its effects. Antihistamines frequently cause mouth dryness and sleepiness. Newer "non sedating" antihistamines are generally thought to be somewhat less effective. Antihistamine side effects that very occasionally occur include urine retention in males and fast heart rate.
Atropine: A drug obtained from belladonna that is administered via injection, eye drops, or in oral form to relax muscles by inhibiting nerve responses. Used to dilate the pupils and as an antispasmodic. See the entire definition of Atropine
Autoimmune: Pertaining to autoimmunity, a misdirected immune response that occurs when the immune system goes awry and attacks the body itself. See the entire definition of Autoimmune
Bacteria: Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). See the entire definition of Bacteria
Bacterial: Of or pertaining to bacteria. For example, a bacterial lung infection.
Blood pressure: The blood pressure is the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. It's measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest. A blood pressure cuff is used to measure the pressure. Elevation of blood pressure is called "hypertension".
Blurred vision: Lack of sharpness of vision with, as a result, the inability to see fine detail. Blurred vision can occur when a person who wears corrective lens is without them. Blurred vision can also be an important clue to eye disease.
Brain: That part of the central nervous system that is located within the cranium (skull). The brain functions as the primary receiver, organizer and distributor of information for the body. It has two (right and left) halves called "hemispheres."
Bulbar: Pertaining to a bulb, in medicine any rounded mass of tissue (that is shaped somewhat like a crocus or tulip bulb). See the entire definition of Bulbar
Bulbar conjunctiva: That part of the conjunctiva, a clear membrane of the eye, which covers the outer surface of the eye. See the entire definition of Bulbar conjunctiva
Chalazion: A cyst of the little glands in the eyelids that make a lubricant which they discharge through tiny openings in the edges of the lids. The lubricant is a fatty substance called sebum characteristic of sebaceous glands. See the entire definition of Chalazion
Chemical reaction: A process in which one substance is transformed into another. Thousands of different types of chemical reactions occur in the body and are essential to its structure and function.
Chloride: The major anion (negatively charged substance) in the blood and extracellular fluid (the body fluid that lies outside cells). Blood and other body fluids have almost the same concentration of chloride ion as sea water. The balance of chloride ion (Cl-) is closely regulated by the body. See the entire definition of Chloride
Complication: In medicine, an additional problem that arises following a procedure, treatment or illness and is secondary to it. A complication complicates the situation.
Congestion: An abnormal or excessive accumulation of a body fluid. The term is used broadly in medicine. Examples include nasal congestion (excess mucus and secretions in the air passages of the nose) seen with a common cold and congestion of blood in the lower extremities seen with some types of heart failure.
Conjunctiva: A thin clear moist membrane that coats the inner surfaces of the eyelids and the outer surface of the eye. See the entire definition of Conjunctiva
Conjunctivitis: Inflammation of the conjunctiva, the membrane on the inner part of the eyelids and the membrane covering the white of the eye. The conjunctival membranes react to a wide range of bacteria, viruses, allergy-provoking agents, irritants and toxic agents. Viral and bacterial forms of conjunctivitis are common in childhood. Conjunctivitis is also called pinkeye and red eye. See the entire definition of Conjunctivitis
Contact dermatitis: A skin condition caused by contact between skin and some substance. Includes irritant contact dermatitis (a rash brought on purely by repeated irritation from a substance such as water causing "dish pan hands") and allergic contact dermatitis (involving a specific sensitivity or allergy to a specific substance such as poison ivy).
Cornea: The clear front window of the eye that transmits and focuses light into the eye. See the entire definition of Cornea
Corneal: Pertaining to the cornea, the clear front window of the eye that transmits and focuses light into the eye.
Decongestant: A drug that shrinks the swollen membranes in the nose and makes it easier to breath. Decongestants can be taken orally or by nasal spray. Decongestant nasal sprays should not be used for more than five days without the doctor's advice, and if so, usually only when accompanied by a nasal steroid. Many decongestant nasal sprays often cause a rebound effect if taken too long. A rebound effect is the worsening of symptoms when a drug is discontinued. This is a result of a tissue dependence on the medication. Decongestants should not be used by patients with high blood pressure (hypertension) unless under doctor's supervision.
Dermatitis: Inflammation of the skin, either due to direct contact with an irritating substance, or to an allergic reaction. Symptoms of dermatitis include redness, itching, and in some cases blistering. See the entire definition of Dermatitis
Dilate: To stretch or enlarge. It comes from the Latin verb "dilatare" meaning "to enlarge or expand."
Dilation: The process of enlargement, stretching, or expansion. The word "dilatation" means the same thing. Both come from the Latin "dilatare" meaning "to enlarge or expand."
Discharge:1.The flow of fluid from part of the body, such as from the nose or vagina. 2. The passing of an action potential, such as through a nerve or muscle fiber. 3. The release of a patient from a course of care. The doctor may then dictate a discharge summary.
Drain: A device for removing fluid from a cavity or wound. A drain is typically a tube or wick. As a verb, to allow fluid to be released from a confined area.
Dry eye: A deficiency of tears. The main symptom is usually a scratchy or sandy feeling as if something is in the eye. Other symptoms may include stinging or burning of the eye; episodes of excess tearing that follow periods of very dry sensation; a stringy discharge from the eye; and pain and redness of the eye. Sometimes people with dry eye experience heaviness of the eyelids or blurred, changing, or decreased vision, although loss of vision is uncommon. See the entire definition of Dry eye
Dry mouth: The condition of not having enough saliva to keep the mouth wet. This is due to inadequate function of the salivary glands. Everyone has dry mouth once in a while when they are nervous, upset or under stress. But if someone has a dry mouth most all of the time, it can be uncomfortable and lead to serious health problems. See the entire definition of Dry mouth
Edema: The swelling of soft tissues as a result of excess water accumulation. See the entire definition of Edema
Electrolyte: An electrolyte is a substance that will dissociate into ions in solution and acquire the capacity to conduct electricity. The electrolytes include sodium, potassium, chloride, calcium and phosphate. Informally, called lytes. (The clue to the word electrolyte is in the lyte which comes from the Greek lytos meaning that may be dissolved.)
Eyelash: One of the familiar stiff hairs that project from the margin of the eyelid. See the entire definition of Eyelash
Eyelid: The lid or cover of the eye, a movable fold of skin and muscle that can be closed over the eyeball or opened at will. Each eye has an upper and a lower lid. An eyelid is also called a palpebra.
Fingernail: A fingernail is produced by living skin cells in the finger. A fingernail consists of several parts including the nail plate (the visible part of the nail), the nail bed (the skin beneath the nail plate), the cuticle (the tissue that overlaps the plate and rims the base of the nail), the nail folds (the skin folds that frame and support the nail on three sides), the lunula (the whitish half-moon at the base of the nail) and the matrix (the hidden part of the nail unit under the cuticle). See the entire definition of Fingernail
Fungal: Pertaining to a fungus. For example, a fungal skin infection.
Fungus: A single-celled or multicellular organism. Fungi can be true pathogens (such as histoplasmosis and coccidioidomycosis) that cause infections in healthy persons or they can be opportunistic pathogens (such as aspergillosis, candidiasis, and cryptococcosis) that cause infections in immunocompromised persons (including cancer patients, transplant recipients, and persons with AIDS). An example of a common fungus is the yeast organism which causes thrush and diaper rash (diaper dermatitis). Fungi are also used for the development of antibiotics, antitoxins, and other drugs used to control various human diseases.
Gland:1. A group of cells that secrete a substance for use in the body. For example, the thyroid gland. 2. A group of cells that removes materials from the circulation. For example, a lymph gland.
Glaucoma: A common eye condition in which the fluid pressure inside the eyes rises because of slowed fluid drainage from the eye. If untreated, it may damage the optic nerve and other parts of the eye, causing the loss of vision or even blindness. See the entire definition of Glaucoma
Headache: A pain in the head with the pain being above the eyes or the ears, behind the head (occipital), or in the back of the upper neck. Headache, like chest pain or back ache, has many causes. See the entire definition of Headache
High blood pressure: Also known as hypertension, high blood pressure is, by definition, a repeatedly elevated blood pressure exceeding 140 over 90 mmHg -- a systolic pressure above 140 with a diastolic pressure above 90. See the entire definition of High blood pressure
Histamine: Substance that plays a major role in many allergic reactions. Histamine dilates blood vessels and makes the vessel walls abnormally permeable.
Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person. See the entire definition of Infection
Inflammation: A basic way in which the body reacts to infection, irritation or other injury, the key feature being redness, warmth, swelling and pain. Inflammation is now recognized as a type of nonspecific immune response. See the entire definition of Inflammation
Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma.
Internal medicine: A medical specialty dedicated to the diagnosis and medical treatment of adults. A physician who specializes in internal medicine is referred to as an internist. A minimum of seven years of medical school and postgraduate training are focused on learning the prevention, diagnosis, and treatment of diseases of adults. Subspecialties of internal medicine include allergy and immunology, cardiology (heart), endocrinology (hormone disorders), hematology (blood disorders), infectious diseases, gastroenterology (diseases of the gut), nephrology (kidney diseases), oncology (cancer), pulmonology (lung disorders), and rheumatology (arthritis and musculoskeletal disorders).
Iris: The iris is the circular, colored curtain of the eye. Its opening forms the pupil. The iris helps regulate the amount of light that enters the eye. See the entire definition of Iris
Itching: An uncomfortable sensation in the skin that feels as if something is crawling on the skin or in the skin, and makes the person want to scratch the affected area. See the entire definition of Itching
Keratitis:Inflammation of the cornea (the transparent structure in the front of the eye).
Keratoconjunctivitis: Inflammation of the eye involving both the cornea and the conjunctiva. See the entire definition of Keratoconjunctivitis
Lacrimal: Pertaining to tears, as in lacrimal gland (tear gland). From the Indo-European dakru meaning a tear (from a weeping eye) which gave rise to the Greek dakry and the Latin lacrima.
Lacrimal gland: A small almond-shaped structure that produces tears. The lacrimal gland is located just above the outer corner of the eye. The lacrimal gland is part of the lacrimal apparatus, the system that forms tears, conveys them through the lacrimal (tear) duct to the eye, and drains the tears. See the entire definition of Lacrimal gland
Lens: The transparent structure inside the eye that focuses light rays onto the retina (the nerve layer that lines the back of the eye, senses light and creates impulses that go through the optic nerve to the brain). The lens was named after the lentil bean because it resembled it in shape and size. See the entire definition of Lens
Lubricant: An oily or slippery substance. A vaginal lubricant may be helpful for women who feel pain during intercourse because of vaginal dryness.
Membrane: A very thin layer of tissue that covers a surface.
Mouth:1. The upper opening of the digestive tract, beginning with the lips and containing the teeth, gums, and tongue. Foodstuffs are broken down mechanically in the mouth by chewing and saliva is added as a lubricant. Saliva contains amylase, an enzyme that digests starch. 2. Any opening or aperture in the body. The mouth in both senses of the word is also called the os, the Latin word for an opening, or mouth. The o in os is pronounced as in hope. The genitive form of os is oris from which comes the word oral.
Mucus: A thick slippery fluid produced by the membranes lining certain organs such as the nose, mouth, throat, and vagina. Mucus is the Latin word for "a semifluid, slimy discharge from the nose." Note that mucus is a noun while the adjective is mucous.
Nasal: Having to do with the nose. Nasal drops are intended for the nose, not (for example) the eyes. The word "nasal" came from the Latin "nasus" meaning the nose or snout.
Nausea:Nausea, is the urge to vomit. It can be brought by many causes including, systemic illnesses, such as influenza, medications, pain, and inner ear disease. When nausea and/or vomiting are persistent, or when they are accompanied by other severe symptoms such as abdominal pain, jaundice, fever, or bleeding, a physician should be consulted.
Nerve: A bundle of fibers that uses chemical and electrical signals to transmit sensory and motor information from one body part to another. See: Nervous system.
Nodule: A small solid collection of tissue, a nodule is palpable (can be felt). It may range in size from greater than 1.0 cm (3/8 inch) to somewhat less than 2 cm (13/16 inch) in diameter. A nodule may be present in the epidermis, dermis or subcutis (at any level in the skin). See the entire definition of Nodule
Nose: The external midline projection from the face. See the entire definition of Nose
Ointment: A medication preparation that is applied topically (onto the skin). An ointment has an oil base whereas a cream is water-soluble. (The word ointment comes from the Latin ungere meaning anoint with oil).
Ophthalmic: Pertaining to the eye. An ophthalmic ointment is designed for the eye.
Ophthalmologist: An eye doctor. A physician practicing ophthalmology. An ophthalmologist is an M.D.
Optic: Having to do with vision.
Optic nerve: The optic nerve connects the eye to the brain. The optic nerve carries the impulses formed by the retina, the nerve layer that lines the back of the eye and senses light and creates impulses. These impulses are dispatched through the optic nerve to the brain, which interprets them as images. Using an ophthalmoscope, the head of the optic nerve can be easily seen. It can be viewed as the only visible part of the brain (or extension of it). See the entire definition of Optic nerve
Optometrist: A health care professional who is licensed to provide primary eye care services:
to examine and diagnose eye diseases such as glaucoma, cataracts, and retinal diseases and, in certain states in the U.S., to treat them;
to diagnose related systemic (bodywide) conditions such as hypertension and diabetes that may affect the eyes;
to examine, diagnose and treat visual conditions such as nearsightedness, farsightedness, astigmatism and presbyopia; and
to prescribe glasses, contact lenses, low vision rehabilitation and medications as well as perform minor surgical procedures such as the removal of foreign bodies.
Orbital: Relating to the orbit, in anatomy the bony cavity that contains the eyeball.
Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. See the entire definition of Pain
Palpebral conjunctiva: The part of the conjunctiva, a clear membrane, that coats the inside of the eyelids. See the entire definition of Palpebral conjunctiva
Parasite: An organism that lives in or on and takes its nourishment from another organism. A parasite cannot live independently. See the entire definition of Parasite
Phosphate: A form of phosphoric acid. Calcium phosphate makes bones and teeth hard.
Photophobia: Painful oversensitivity to light. For example, there is photophobia in measles (rubeola). Keeping the lights dim or the room darkened may be useful. Sunglasses may also help. See the entire definition of Photophobia
Pubis: The front center portion of the pelvis.
Pupil: The opening of the iris. The pupil may appear to open (dilate) and close (constrict) but it is really the iris that is the prime mover; the pupil is merely the absence of iris. The pupil determines how much light is let into the eye. Both pupils are usually of equal size. If they are not, that is termed anisocoria (from "a-", not + "iso", equal + "kore", pupil = not equal pupils). See the entire definition of Pupil
Radiation:1. Rays of energy. Gamma rays and X-rays are two of the types of energy waves often used in medicine. 2. The use of energy waves to diagnose or treat disease. See also: Irradiation.
Rebound: Return of the original symptoms when maneuvers or treatment is discontinued.
Recurrent: Back again. A recurrent fever is a fever that has returned after an intermission: a recrudescent fever.
Reflex: A reaction that is involuntary. The corneal reflex is the blink that occurs with irritation of the eye. The nasal reflex is a sneeze.
Retina: The retina is the nerve layer that lines the back of the eye, senses light, and creates impulses that travel through the optic nerve to the brain. There is a small area, called the macula, in the retina that contains special light-sensitive cells. The macula allows us to see fine details clearly. See the entire definition of Retina
Rosacea: A chronic skin disease that affects the middle third of the face with persistent redness over the areas of the face and nose that normally blush: mainly the forehead, the chin and the lower half of the nose. The tiny blood vessels in these areas enlarge (dilate) and become more visible through the skin, appearing like tiny red lines (called telangiectasias). Pimples can occur that look like teenage acne. See the entire definition of Rosacea
Sclera: The tough white outer coat over the eyeball that covers approximately the posterior five-sixths of its surface. The sclera is continuous in the front of the eye with the cornea and in the back of the eye with the external sheath of the optic nerve. See the entire definition of Sclera
Scrub:1. As a verb, to wash the hands and forearms very thoroughly, as before engaging in surgery. To scrub implies the use of a brush (and often an implement to clean under the nails). To scrub, to scrub in (on a surgical procedure), and to scrub up are synonymous. 2. As a noun, a person who scrubs, as for surgery. 3. As an adjective, pertaining to scrubbing in for surgery, as a scrub nurse or a scrub tech.
Scrubs: A protective garment designed to be worn by the doctor, nurse, and others in the operating room. The garment was originally a gown. Scrubs now include the shirt and pants worn by those who scrub in for surgery. See the entire definition of Scrubs
Seborrheic dermatitis: A medical name for what is popularly called seborrhea.
Sensitivity:1. In psychology, the quality of being sensitive. As, for example, sensitivity training, training in small groups to develop a sensitive awareness and understanding of oneself and of ones relationships with others. 2. In disease epidemiology, the ability of a system to detect epidemics and other changes in disease occurrence. 3. In screening for a disease, the proportion of persons with the disease who are correctly identified by a screening test. 4. In the definition of a disease, the proportion of persons with the disease who are correctly identified by defined criteria.
Sensory: Relating to sensation, to the perception of a stimulus and the voyage made by incoming (afferent) nerve impulses from the sense organs to the nerve centers. See the entire definition of Sensory
Sodium: The major positive ion (cation) in fluid outside of cells. The chemical notation for sodium is Na+. When combined with chloride, the resulting substance is table salt. See the entire definition of Sodium
Staphylococcus: A group of bacteria that cause a multitude of diseases. Under a microscope, Staphylococcus bacteria are round and bunched together. They can cause illness directly by infection, or indirectly through products they make, such as the toxins responsible for food poisoning and toxic shock syndrome. The best known member of the Staphylococcus family is Staphylococcus aureus. Staphylococcus are the main culprit in hospital-acquired infections, and cause thousands of deaths every year.
Substance:1. Material with particular features, as a pressor substance. 2. The material that makes up an organ or structure. Also known in medicine as the substantia. 3. A psychoactive drug as, for example, in substance abuse.
Syndrome: A set of signs and symptoms that tend to occur together and which reflect the presence of a particular disease or an increased chance of developing a particular disease. See the entire definition of Syndrome
Taste: Taste belongs to our chemical sensing system, or the chemosenses. The complicated process of tasting begins when molecules released by the substances stimulate special cells in the mouth or throat. These special sensory cells transmit messages through nerves to the brain where specific tastes are identified. See the entire definition of Taste
Tear: A drop of the salty secretion of the lacrimal glands which serves to moisten the conjunctiva and cornea.
Therapeutic: Relating to therapeutics, that part of medicine concerned specifically with the treatment of disease. The therapeutic dose of a drug is the amount needed to treat a disease. See the entire definition of Therapeutic
Trauma: Any injury, whether physically or emotionally inflicted. "Trauma" has both a medical and a psychiatric definition. Medically, "trauma" refers to a serious or critical bodily injury, wound, or shock. This definition is often associated with trauma medicine practiced in emergency rooms and represents a popular view of the term. In psychiatry, "trauma" has assumed a different meaning and refers to an experience that is emotionally painful, distressful, or shocking, which often results in lasting mental and physical effects. See the entire definition of Trauma
Tricyclic antidepressants (TCAs): One of a class of medications used to treat depression. The tricyclic antidepressants (TCAs) are also used for some forms of anxiety, fibromyalgia, and the control of chronic pain. See the entire definition of Tricyclic antidepressants
UV radiation: Ultraviolet radiation. Invisible rays that are part of the energy that comes from the sun, can burn the skin, and cause skin cancer. UV radiation is made up of three types of rays -- ultraviolet A (UVA), ultraviolet B (UVB), and ultraviolet C (UVC). See the entire definition of UV radiation
Uveitis: Inflammation of the uvea, the part of the eye that collectively refers to the iris, the choroid of the eye, and the ciliary body. The uvea provides most of the blood supply to the retina. Uveitis as a rule signifies inflammation involving the iris, choroid, and ciliary body -- all three components of the uveal tract. See the entire definition of Uveitis
Virus: A microorganism smaller than a bacteria, which cannot grow or reproduce apart from a living cell. A virus invades living cells and uses their chemical machinery to keep itself alive and to replicate itself. It may reproduce with fidelity or with errors (mutations)-this ability to mutate is responsible for the ability of some viruses to change slightly in each infected person, making treatment more difficult. See the entire definition of Virus
Viruses: Small living particles that can infect cells and change how the cells function. Infection with a virus can cause a person to develop symptoms. The disease and symptoms that are caused depend on the type of virus and the type of cells that are infected.
Vitreous: A clear, jelly-like substance that fills the middle of the eye. Also called the vitreous humor, "humor" in medicine referring to a fluid (or semifluid) substance.
Pink eye, also called conjunctivitis, is redness or irritation of the conjunctivae, the membranes on the inner part of the eyelids and the membranes covering the whites of the eyes. These membranes react to a wide range of bacteria, viruses, allergy-provoking agents, irritants, and toxic agents.
A sty (sometimes spelled stye) is a tender, painful red bump located at the base of an eyelash or on, inside, or under the eyelid, which is the result of an acute infection of the oil glands of the eyelid. Complications of a sty can be blepharitis and chalazion.
Sjögren's syndrome is an autoimmune disease involving the abnormal production of extra antibodies that attack the glands and connective tissue. Sjögren's syndrome with gland inflammation (resulting dry eyes and mouth, etc.) that is not associated with another connective tissue disease is referred to as primary Sjögren's syndrome. Sjögren's syndrome that is also associated with a connective tissue disease, such as rheumatoid arthritis, systemic lupus erythematosus, or scleroderma, is referred to as secondary Sjögren's syndrome. Though there is no cure for Sjögren's syndrome, the symptoms may be treated by using lubricating eye ointments, drinking plenty of water, humidifying the air, and using glycerin swabs. Medications are also available to treat dry eye and dry mouth.
Retinal detachment is the separation of the retina from its attachments to the underlying eye tissue. Symptoms of retinal detachment include flashing lights and floaters. Highly nearsighted young adults and those who've had cataract surgery are at higher risk for retinal detachment.
Glaucoma is a common eye condition in which the fluid pressure inside the eye rises because of slowed fluid drainage from the eye. If untreated, glaucoma may damage the optic nerve and other parts of the eye, causing the loss of vision or even blindness.
Eye floaters are deposits or condensation that forms in the eye's vitreous humor. These deposits cast shadows on the retina, and as the eye moves, the deposits shift position, making it appear as though the shadows are moving or floating.
A subconjunctival hemorrhage is bleeding under the eye's conjunctiva. There is usually no obvious cause for a subconjunctival hemorrhage, but it may be caused by sneezing, vomiting, infections on the outside of the eye, coughing, and clotting disorders. Symptoms and signs include blood in the white of the eye and a sense of fullness under the lid. No treatment is needed.
Dry eyes are caused by an imbalance in the tear-flow system of the eye, but also can be caused by the drying out of the tear film. This can be due to dry air created by air conditioning, heat, or other environmental conditions.
A cataract is an eye disease that causes the eye's lens to become cloudy and opaque with decreased vision. Causes of cataracts include diabetes, hypothyroidism, certain genetic illnesses, hyperparathyroidism, atopic dermatitis, and certain medications. Symptoms and signs include a decrease in vision and a whitish color to the affected eye. Treatment depends upon the patient's specific visual needs and may involve cataract surgery.
Blepharitis is inflammation of the eyelids. Acne rosacea, Staphylococcal bacteria, allergies, sensitivities to makeup or contact lens solutions, head lice, or other conditions may cause blepharitis. Symptoms and signs include itchy eyelids, burning sensation in the eyes, crusting of the eyelids, light sensitivity, red, swollen eyelids, loss of eyelashes, and dandruff of the lashes and eyebrows. Proper eyelid hygiene and a regular cleaning routine controls blepharitis.
Eye strain is a symptom caused by looking at something for a long time. Symptoms and signs include redness, light sensitivity, headaches, and blurred vision. Symptoms may be treated by closing the eyes and taking a break from the visual task.
Uveitis is inflammation of the eye. Symptoms include blurred vision, eye pain, eye redness, and floating spots before the eyes. Treatment may involve prescription eyedrops, antibiotics, and wearing dark glasses.
The most common cause of a black eye is due to an injury to the face or head. Most black eye injuries are minor and heal on their own, however, some may lead to significant injury. In addition to trauma to the face, cosmetic surgery can cause a black eye(s) as a side effect. People should be aware of the situations in which medical care should be sought immediately for a black eye.
Astigmatism is a common eye condition that's easily corrected by eyeglasses, contact lenses, or surgery. Symptoms of astigmatism are headaches, fatigue, eyestrain and blurred vision.
Blindness is the state of being sightless. Causes of blindness include macular degeneration, stroke, cataract, glaucoma, infection and trauma. Symptoms and signs may include eye pain, eye discharge, or the cornea or pupil turning white. Treatment of blindness depends upon the cause of the blindness.
Age-related macular degeneration (AMD) is a disease that gradually destroys the central vision. In people over 60, AMD is a leading cause of vision loss. Wet AMD occurs when abnormal blood vessels behind the retina start to grow under the macula, leaking blood and fluid and causing rapid vision loss. In dry AMD, light-sensitive cells slowly break down in the macula, resulting in gradual vision loss. Pain is not associated with either form of AMD.
Diabetes and eye problems are generally caused by high blood sugar levels over an extended period of time. Types of eye problems in a person with diabetes include glaucoma, cataracts, and retinopathy. Examples of symptoms include blurred vision, headaches, eye aches, pain, halos around lights, loss of vision, watering eyes. Treatment for eye problems in people with diabetes depend on the type of eye problem. Prevention of eye problems include reducing blood pressure, cholesterol levels, quitting smoking, and maintaining proper blood glucose levels.
Double vision (diplopia) is a symptom that my indicate Graves' disease, myasthenia gravis, stroke, multiple sclerosis, Guillain-Barre syndrome, diabetes, cataracts, aneurysm, brain tumor, or migraine. Symptoms and signs include eye pain, droopy eyelids, nausea, headache, and a cross-eyed appearance. Treatment of double vision depends upon the underlying cause.
eye. Read about symptoms, signs, diagnosis, treatment, and prognosis.
Coats' disease is a rare eye condition that typically progresses to vision loss or blindness in one eye. Gradual vision loss is usually the first symptom, followed by a cloudy white or yellow pupil due to the presence of a cataract. Treatment focuses on limiting the blood vessel progression and may involve cryotherapy or laser photocoagulation.
Nonprescription eyeglasses are available over the counter (OTC) and are typically used by people who can no longer read fine print. OTC trifocals are helpful for those who require multiple distances or focal lengths for near and intermediate tasks. OTC sunglasses should offer 100% protection from the sun's UVA and UVB rays. OTC magnifying glasses are useful for viewing tiny objects or fine print.
A visual field test is a method of measuring an individual's entire scope of vision, that is their central and peripheral (side) vision. Visual field testing actually maps the visual fields of each eye individually. The visual field test is a subjective examination, requiring the patient to understand the testing instructions, fully cooperate, and complete the entire test in order to provide useful information.
What is a visual field test used for?
Visual field testing is most frequently used to detect any signs of glaucoma damage to the optic nerve. In addition, visual field tests are useful for detection of central or peripheral retinal disease, eyelid conditions such as ptosis or drooping, optic nerve disease, and diseases affecting the visual pathways within the brain. The visual pathways carry information from the eye to the visual or occipital cortex in the brain, where this information is proces...
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