Cataracts Glossary of Terms
The following are health and medical definitions of terms that appear in the Cataracts article.
Aging: The process of becoming older, a process that is genetically determined and environmentally modulated. Ambulatory: Able to ambulate, to walk about, not bed-ridden or hospitalized. 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. Anesthesia: Loss of feeling or awareness. A general anesthetic puts the person to sleep. A local anesthetic causes loss of feeling in a part of the body such as a tooth or an area of skin without affecting consciousness. Regional anesthesia numbs a larger part of the body such as a leg or arm, also without affecting consciousness. The term "conduction anesthesia" encompasses both local and regional anesthetic techniques. Many surgical procedures can be done with conduction anesthesia without significant pain. In many situations, such as a C-section, conduction anesthesia is safer and therefore preferable to general anesthesia. However, there are also many types of surgery in which general anesthesia is clearly appropriate. Anesthesiologist: A physician or, less often, a dentist who is specialized in the practice of anesthesiology, the branch of medicine involving the use of drugs or other agents that cause insensibility to pain. Anterior: The front, as opposed to the posterior. The anterior surface of the heart is toward the breast bone (the sternum). Astigmatism: A common form of visual impairment in which part of an image is blurred, due to an irregularity in the curvature of the front surface of the eye, the cornea. The curve of the cornea is shaped more like an American football or a rugby ball rather than a normal spherical basketball. Light rays entering the eye there are not uniformly focused on the retina. Rays entering through the more-curved surface are focused before the rays coming through the less-curved surface. The light is focused clearly along one plane but is blurred along the other. The result is blurred vision at all distances. Only part of what you are looking at is in clear focus at any one time. 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." Capsule: Capsule has many meanings in medicine including the following:
See the entire definition of Capsule Cataract: A clouding or loss of transparency of the lens in the eye as a result of tissue breakdown and protein clumping. There are many causes of cataracts, including aging, cortisone medication, trauma, diabetes, and other diseases. Cataracts affect most people who live into an old age. Symptoms include double or blurred vision and sensitivity to light and glare. A physician can diagnose cataracts by examining the eyes with a viewing instrument. Sunglasses can help to prevent cataracts. Cataract surgery: Removal of the clouded lens (the cataract) in its entirety by surgery, usually followed by replacement of the lens with an intraocular lens (IOL) made of plastic, silicone, acrylic or other material. The operation typically takes about an hour, is done under local anesthetic only, and does not require hospitalization. See the entire definition of Cataract surgery Congenital: Present at birth. A condition that is congenital is one that is present at birth. There are numerous uses of "congenital" in medicine. There are, for example, congenital abnormalities. (For more examples, see below.) Contrast: Short for "contrast media." Contrast media are X-ray dyes used to provide contrast, for example, between blood vessels and other tissue. Cornea: The clear front window of the eye that transmits and focuses light into the eye. Corneal: Pertaining to the cornea, the clear front window of the eye that transmits and focuses light into the eye. Cortex: The outer portion of an organ. Cortical: Having to do with the cortex, the outer portion of an organ. Diabetes: Refers to diabetes mellitus or, less often, to diabetes insipidus. Diabetes mellitus and diabetes insipidus share the name "diabetes" because they are both conditions characterized by excessive urination (polyuria). 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." Enzyme: A protein (or protein-based molecule) that speeds up a chemical reaction in a living organism. An enzyme acts as catalyst for specific chemical reactions, converting a specific set of reactants (called substrates) into specific products. Without enzymes, life as we know it would not exist. Essential: 1. Something that cannot be done without. Eye chart test: This test measures how well you see at various distances. The eye chart itself -- the usual one is called Snellen's chart -- is imprinted with block letters that line-by-line decrease in size, corresponding to the distance at which that line of letters is normally visible. Focal: Pertaining to a focus which in medicine may refer to: 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. Herbal: 1. An adjective, referring to herbs, as in an herbal tea. Implant: 1. To embed; to set in firmly. In embryology, the fertilized egg implants in the uterine lining 6 or 7 days after conception (fertilization). In medicine today, many things may be implanted. Implantation: The act of setting in firmly. Incision: A cut. When making an incision, a surgeon is making a cut. 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. 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. Intervention: The act of intervening, interfering or interceding with the intent of modifying the outcome. In medicine, an intervention is usually undertaken to help treat or cure a condition. For example, early intervention may help children with autism to speak. "Acupuncture as a therapeutic intervention is widely practiced in the United States," according to the National Institutes of Health. From the Latin intervenire, to come between. Intraocular: In the eye. The intraocular pressure is the pressure within the eye. Intraocular lens: An artificial lens made of plastic, silicone, acrylic or other material that is implanted inside the eye during cataract surgery. Abbreviated IOL. 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. Laser: A powerful beam of light that can produce intense heat when focused at close range. Lasers are used in medicine in microsurgery, cauterization, for diagnostic purposes, etc. For example, lasers are employed in microsurgery to cut tissue and remove tissue. LASIK: Abbreviation standing for laser-assisted in situ keratomileusis, a kind of laser eye surgery designed to change the shape of the cornea to eliminate or reduce the need for glasses and contact lenses in cases of severe myopia (nearsightedness). 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. Medical history: 1. In clinical medicine, the patient's past and present which may contain clues bearing on their health past, present, and future. The medical history, being an account of all medical events and problems a person has experienced, including psychiatric illness, is especially helpful when a differential diagnosis is needed. Microscope: An optical instrument that augments the power of the eye to see small objects. The name microscope was coined by Johannes Faber (1574-1629) who in 1628 borrowed from the Greek to combined micro-, small with skopein, to view. Although the first microscopes were simple microscopes, most (if not all) optical microscopes today are compound microscopes. Multifocal: Having to do with two or more foci or arising from two or more places. For example, aortic aneurysm disease is often multifocal and needs total aortic screening for diagnosis. Nearsightedness: The ability to see near objects more clearly than distant objects. Also called myopia . Operating room: A facility equipped for performing surgery. Abbreviated OR. Ophthalmologist: An eye doctor. A physician practicing ophthalmology. An ophthalmologist is an M.D. Ophthalmology: The art and science of eye medicine. 
Otolaryngology: A medical and surgical specialty concerned with the diagnosis, management, and treatment of diseases and disorders of the ear, nose, throat (ENT) and related structures of the head and neck, including the sinuses, larynx (voice box), oral cavity, and upper pharynx (mouth and throat). Subspecialty areas within otolaryngology include pediatric otolaryngology (children), otology/neurotology (ears, balance, and tinnitus), allergy, facial plastic and reconstructive surgery, head and neck, laryngology (throat), and rhinology (nose). Some otolaryngologists limit their practices to one or more of these seven areas. Otolaryngology is commonly called ENT. It is the oldest medical specialty in the US. Outpatient: A patient who is not an inpatient (not hospitalized) but instead is cared for elsewhere -- as in a doctor's office, clinic, or day surgery center. The term outpatient dates back at least to 1715. Outpatient care today is also called ambulatory care. 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. Peripheral: Situated away from the center, as opposed to centrally located. Peripheral vision: Side vision. The ability to see objects and movement outside of the direct line of vision. Peripheral vision is the work of the rods, nerve cells located largely outside the macula (the center) of the retina. The rods are also responsible for night vision and low-light vision but are insensitive to color. As opposed to central vision. Phacoemulsification: A procedure in which the lens clouded by a cataract is broken up by ultrasound, irrigated, and suctioned out. Most cataract surgery today is performed using phacoemulsification. Before the advent of this technique, people with cataracts could expect a 10-day hospital stay followed by a lengthy recovery. Today, it is an outpatient procedure. Instead of making a large incision in the eye and removing the lens, the ophthalmologist can make a tiny one and then insert an ultrasonic tip which, vibrating thousands of times a second, breaks up the cataracts without damaging the surrounding tissue. The remains of the cataract are suctioned out. Pharmacy: A location where prescription drugs are sold. A pharmacy is, by law, constantly supervised by a licensed pharmacist. Posterior: The back or behind, as opposed to the anterior. Preoperative: Before surgery. As opposed to postoperative, after surgery. Prescription: A physician's order for the preparation and administration of a drug or device for a patient. A prescription has several parts. They include the superscription or heading with the symbol "R" or "Rx", which stands for the word recipe (meaning, in Latin, to take); the inscription, which contains the names and quantities of the ingredients; the subscription or directions for compounding the drug; and the signature which is often preceded by the sign "s" standing for signa (Latin for mark), giving the directions to be marked on the container. Probe: (1) In surgery, a probe is a slender flexible rod with a blunt end used to explore, for example, an opening to see where it goes. (2) In molecular genetics, a probe is a labeled bit of DNA or RNA used to find its complementary sequence or locate a particular clone like homing in on a needle in a haystack. Protein: A large molecule composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. Proteins: Large molecules composed of one or more chains of amino acids in a specific order determined by the base sequence of nucleotides in the DNA coding for the protein. 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). 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.
Refraction: In ophthalmology, the bending of light that takes place within the human eye. Resident: In medicine, a physician who has finished medical school and internship and is now receiving training in a specialized area as, for example, surgery, internal medicine, pathology or radiology. Board certification in all medical and surgical specialties requires the satisfactory completion of a residency program. 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. Retinal: Pertaining to the retina, the extraordinary layer of neurons (nerve cells) that line the back of the eye, which can sense light and create impulses capable of voyaging through the optic nerve to the brain where the impulses are recognized as an image. Retinal detachment: A separation of the retina from its connection at the back of the eye. The separation usually results from a tear (that is, a rent or rip, not a tear drop) in the retina. The tear often occurs when the vitreous gel pulls loose or separates from its attachment to the retina, usually in the outside edges of the eye. The vitreous is a clear gel that fills most of the inside of the eye between the retina and the lens. If the retina is weak when the vitreous gel pulls loose, the retina will tear. This rip is sometimes accompanied by bleeding, or hemorrhage, if a blood vessel is also torn. Secondary cataract: See: Cataract, secondary. Sensation: In medicine and physiology, sensation refers to the registration of an incoming (afferent) nerve impulse in that part of the brain called the sensorium, which is capable of such perception. Therefore, the awareness of a stimulus as a result of its perception by sensory receptors. (Sensory is here synonymous with sensation.) 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. Sleep: The body's rest cycle. Statins: A class of drugs that lower cholesterol. Surgeon: A physician who treats disease, injury, or deformity by operative or manual methods. A medical doctor specialized in the removal of organs, masses and tumors and in doing other procedures using a knife (scalpel). The definition of a "surgeon" has begun to blur in recent years as surgeons have begun to minimize the cutting, employ new technologies that are "minimally invasive," use scopes, etc. Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office. Tonometry: A standard eye test that determines the fluid pressure inside the eye. Increased pressure is a possible sign of glaucoma, a common and potentially very serious eye problem if not detected and treated promptly. It is recommended that adults over age 40 have tonometry for glaucoma every 3 to 5 years by having their eye pressures measured. Topical: Pertaining to a particular surface area. A topical agent is applied to a certain area of the skin and is intended to affect only the area to which it is applied. Whether its effects are indeed limited to that area depends upon whether the agent stays where it is put or is absorbed into the blood stream. 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. Ultrasound: High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during pregnancy. 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). Visual acuity: The clarity or clearness of the vision, a measure of how well a person sees. The ability to distinguish details and shapes of objects; also called central vision. Visual acuity test: This test measures how well you see at various distances. It is the familiar eye chart test. Vital: Necessary to maintain life. Breathing is a vital function. Vitamins: The word "vitamin" was coined in 1911 by the Warsaw-born biochemist Casimir Funk (1884-1967). At the Lister Institute in London, Funk isolated a substance that prevented nerve inflammation (neuritis) in chickens raised on a diet deficient in that substance. He named the substance "vitamine" because he believed it was necessary to life and it was a chemical amine. The "e" at the end was later removed when it was recognized that vitamins need not be amines.
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Cigarette Smoking Overview
Cigarette smoking remains a leading contributor to death and illness among Americans. Every year, roughly 440,000 Americans die from illnesses caused by tobacco use, accounting for nearly one-fifth of all deaths. Tobacco use costs the nation about $100 billion each year in direct medical expenses and in lost productivity for a total cost of about 200 billion per year as estimated by the CDC.
About 23% of all American adults (46.2 million people) smoke. This number has remained constant for several years despite government efforts through Healthy People 2000 and Healthy People 2010 to lower those percentages. Slightly more men (28.1%) smoke than women (23.5%). Hispanics (16.7%) and Asian Americans (12.4%) smoke less than whites (24.0%) or African Americans (22.3%). In younger age groups, almost 27% of those 18 to 24 years old are current smokers.
Nevertheless, significant progress has been made since 1964, when the Surgeon Genera...
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