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Eye Care Reference Information
Age Related Macular Degeneration (ARMD): the
breaking down of the macula, the back portion of the retina that is
responsible for clear vision. There are two main types of ARMD. (1)
Involutional ARMD (Dry ARMD) results in a slow, progressive loss of
central vision (usually not beyond 20/200). There is currently no
treatment. (2) Exudative (Wet ARMD) results in distorted or blurred vision
caused by the growth of neovascular membrane in or near the macula. May be
treated if diagnosed early without significant loss of central vision.
(Ref: WebMD)
Amblyopia: a condition in which there is loss
of vision for no apparent reason; the eye appears healthy, but vision is
poor. This is also commonly known as "lazy eye”. The decreased vision is
not correctable with optical devices. Patients with severe nutritional
deprivation or vitamin B12 deficiency may experience simulated amblyopia.
Complete recovery is possible with good diet and B vitamins, however,
prolonged deficiency results in permanent loss of central vision. (Ref:
WebMD)
Anisometropia: inequality of considerable degree in
the refractive power of the two eyes, i.e. one eye is nearsighted and the
other is farsighted).
Annual Replacement Lenses:
conventional contact lenses that are replaced yearly.
Anterioruveitis: an inflammation of the middle layer of the eye, which
includes the iris (colored part of the eye) and adjacent tissue, known as
the ciliary body. If untreated, it can cause permanent damage and loss of
vision from the development of glaucoma, cataract or retinal edema.
Anterior uveitis can occur as a result of trauma to the eye, such as a
blow or foreign body penetrating the eye. It can also be a complication of
other eye disease, or it may be associated with general health problems
such as rheumatoid arthritis, rubella and mumps. In most cases, there is
no obvious underlying cause. Signs/symptoms may include a red, sore and
inflamed eye, blurring of vision, sensitivity to light and a small pupil.
(Ref: AOA)
Aphakic Lens: a lens designed to meet the needs
of patients that have had their crystalline lens removed due to the
development of cataracts.
Aspheric Lens: a not-quite-spherical lens that can improve contrast sensitivity and depth
perception for borderline astigmats or emerging presbyopes. The power
changes gradually, from the center to the edge of the
lens.
Astigmatism: a condition caused by an irregularly
shaped cornea (shaped more like a football than a baseball), resulting in
two focal points causing light images to focus on two separate points in
the eye and resulting in a blurred or distorted image.
Bifocal/Multifocal Lens: contains two or more
viewing zones allowing for one to see distant, intermediate and near
objects.
Blepharitis: a chronic or long term inflammation of
the eyelids and eyelashes. It affects people of all ages. Among the most
common causes of blepharitis are poor eyelid hygiene, excessive oil
produced by the glands in the eyelid, a bacterial infection (often
staphylococcal), or an allergic reaction. (Ref: AOA)
Cataracts: a painless, cloudy area in the lens
of the eye. A cataract blocks the passage of light from the lens to the
nerve layer (retina) at the back of the eye, and may cause vision
problems. (Ref: WebMD) Cataracts can be surgically removed and replaced
with an intraocular lens implant, restoring vision.
CMV Retinitis: CMV stands for Cytomegalovirus. This virus is a common
source of infection in humans and generally lays dormant in the body
without producing symptoms. When CMV attacks the cells in the retina, the
condition is called CMV Retinitis. CMV Retinitis develops in 20% to 40% of
patients with AIDS, making it the most common AIDS-related infection of
the eye. In the early stages of CMV, you may not notice any change in
vision, or you may notice "floating" particles or loss of peripheral
vision. The condition often begins in one eye and then may appear in the
other. If left untreated, the disease progresses and can cause serious
loss of vision. CMV Retinitis is not associated with light sensitivity,
pain, or redness of the eye.
Color Blindness or Color vision deficiency: A nonspecific term for
congenital or acquired impairment of color discrimination, usually reds and greens
but can also be blues and yellows. It seems that more males are affected,
with 7% of males showing this deficiency, and only about 0.5% of females. Color
vision deficiency is not a disease or degenerative condition, though occasionally an
acquired color vision deficiency may be a symptom of other health
problems. (Ref: Contact Lens Council)
Conjunctivitis (“pink eye”): often called "pink eye," it is
an inflammation of the conjunctiva, the tissue that lines the inside of
the eyelid and helps keep the eyelid and eyeball moist. Viruses, bacteria,
irritating substances (shampoo, dirt, smoke, pool chlorine), sexually transmitted diseases
(STDs), or allergens (substances that cause allergies) can all cause
conjunctivitis. Pink eye caused by bacteria, viruses, or STDs can spread
easily from person to person but is not a serious health risk if diagnosed
promptly; allergic conjunctivitis is not contagious. (Ref:
WebMD)
Contact Lens: a thin plastic lens designed to fit
over the cornea, usually for the correction of refractive error. (Ref:
Contact Lens Council)
Conventional Wear Contact Lens:
a contact lens prescribed to be replaced after 12 months or as directed by
the eye care practitioner.
Cornea: The transparent surface
that covers the pupil and iris (like a watch crystal), and provides most
of the eye's optical power. Contact lenses are worn over the corneal
surface. (Ref: Contact Lens Council)
Corneal Dystrophy:
abnormal corneal development resulting in structural or clarity defects.
The cornea owes its transparency to the presence of a regular lattice
structure of collagen fibers. Anything that affects this regularity,
results in loss of the transparency, which is essential for good corneal
function and health. Corneal dystrophies form a group of rare disorders
that usually affect both eyes. They may be present at birth, but more
frequently develop during adolescence and progress gradually throughout
life. Some forms are mild, others severe. (Ref: RNIB
website)
Crystalline Lens: The natural lens of the eye, a
transparent structure suspended behind the iris. Focuses light rays on the
retina and changes shape to change the focus of the eye for different
distances. (Ref: Contact Lens Council)
Custom Toric Contact Lens: corrects mid to high levels
of astigmatism and is generally manufactured on an Rx basis specifically for
a particular individual.
Daily Wear Contact Lens: these lenses are
intended to be worn during waking hours (less than 24 hours) and cleaned
and disinfected each time they are removed from the
eye.
Deposits: accumulation of substances, usually tear film
components (protein), onto the contact lens surface and/or in the lens
material. Types include protein, mucus, lipid, inorganic and soilant.
(Ref: Contact Lens Council)
Depth Perception: the ability to
judge the relative distance of objects and the spatial relationship of
objects at different distances. (Ref: Contact Lens
Council)
Diabetic Retinopathy: an eye disease caused by
diabetes. Diabetes damages the small blood vessels in the retina, which
can lead to vision loss. (Ref: WebMD)
Disinfecting Solution:
an agent that kills surface bacteria and microorganisms. (Ref: Contact
Lens Council)
Disposable Contact Lens: a single use lens.
Defined by the U.S. Food and Drug Administration as a contact lens that is
used one time and discarded. These can be either worn for a single day or,
if they are also "extended wear" lenses, up to seven days, depending on
the wearing schedule prescribed by the eye care professional. Any lens
that is intended to be removed from the eye, cleaned, rinsed, disinfected,
and reinserted does not qualify for inclusion in this category under the
FDA definition. (Ref: Contact Lens Council)
Dry Eyes: : Dry
eye means that your eyes do not produce enough tears or that you produce
tears which do not have the proper chemical composition. Often, dry eye is
part of the natural aging process. It can also be caused by blinking or
eyelid problems, medications like antihistamines, oral contraceptives and
antidepressants, a dry climate, wind and dust, general health problems
like arthritis or Sjogren's syndrome and chemical or thermal burns to your
eyes. symptoms may include irritated, scratchy, dry, uncomfortable or red
eyes, a burning sensation or feeling of something foreign in your eyes and
blurred vision. Excessive dry eyes may damage eye tissue, scar your cornea
(the front covering of your eyes) and impair vision and make contact lens
wear difficult. (Ref: AOA)
Emmetropia: a condition generally known as
“normal vision” where light rays from distant objects are focused on the
retina so vision is sharp and clear (20/20). (Ref: Contact Lens
Council)
Extended Wear Contact Lens: Contact lens designed
to be worn round-the-clock for intervals of one to seven days. (Ref:
Contact Lens Council)
Farsightedness (Hyperopia): People with
farsightedness (hyperopia) have difficulty seeing objects close up.
Farsightedness (Hyperopia) occurs when the eyeball is too short from front
to back, or the eye's focusing mechanism is too weak, causing light rays
to be focused behind, rather than on the retina. (Ref: Contact Lens
Council)
Finished Inside Polymerization System (FIPS™): a
contact lens manufacturing technique involving precision machining the
back surface geometry of a lens onto a hardened stainless steel
insert.
Floaters and Spots: small, semi-transparent or
cloudy specks or particles within the vitreous, the clear, jelly-like
fluid that fills the inside of your eyes. They appear as specks of various
shapes and sizes, threadlike strands or cobwebs. Since they are within
your eyes, they move as your eyes move and seem to dart away when you try
to look at them directly. Spots are often caused by small flecks of
protein or other matter trapped during the formation of your eyes before
birth. They can also result from deterioration of the vitreous fluid, due
to aging; or from certain eye diseases or injuries.
Frequent and Planned Replacement Contact Lenses: see “Replacement
Schedule”
Glaucoma: A condition in which the pressure
inside the eye is elevated to a point that can damage the optic nerve and
cause a loss of peripheral vision, or blindness. (Ref: Contact Lens
Council)
Hard Contact Lens: also known as PMMA lenses,
these traditional lenses are made from
polymethylmethacrylate.
Hydrophilic Polymers: a plastic that
has been designed to hold water. This attribute makes the "water loving"
plastics comfortable to wear and assist with the transfer of oxygen from
the atmosphere to the corneal surface.
Hyperopia
(Farsightedness): People with hyperopia (farsightedness) have
difficulty seeing objects close up. Hyperopia (farsightedness) occurs when
the eyeball is too short from front to back, or the eye's focusing
mechanism is too weak, causing light rays to be focused behind, rather
than on the retina. (Ref: Contact Lens Council)
Infections of the Eye: bacteria, viruses, and
fungi are among the causes of inflammation. Every area of the eye is
susceptible to attack by a large variety of
organisms.
Intraocular Lens (IOL): a plastic lens implanted
in place of the crystalline lens (either behind the cornea or behind the
iris) during cataract surgery. (Ref: Contact Lens
Council)
Iris: the colored portion of the eye that regulates
the amount of light entering the eye by changing the size of the
pupil.
J-1: the line on an eye chart that determines
whether or not the patient needs glasses or contact lenses for
reading.
Keratoconus: is a vision disorder that occurs
when the normally round cornea (the front part of the eye) becomes thin
and irregular (cone) shaped. This abnormal shape prevents the light
entering the eye from being focused correctly on the retina and causes
distortion of vision. (Ref: AOA)
LASIK: abbreviation for Laser-Assisted In Situ
Keratomileusis. A kind of laser surgery designed to improve focus by
altering the shape of the cornea. (Ref: Contact Lens
Council)
Lathe cutting: a manufacturing technique by which
the back surface geometry of the lens is shaped by precision
machining.
Lazy Eye: a condition in which there is loss of
vision for no apparent reason; the eye appears healthy, but vision is
poor. This is also known as amblyopia. The decreased vision is not
correctable with optical devices.
Methafilcon: a hydrophilic material used to
produce contacts that are highly durable, comfortable to wear and easy to
handle.
Monovision: a treatment technique that is often
prescribed for people age 40 and over who are affected by presbyopia.
Presbyopia occurs when, as part of the natural aging process, the eye’s
crystalline lens loses its ability to bring close objects into clear
focus. Monovision means wearing a contact lens for near vision on one eye
and, if needed, a lens for distance vision on the other eye. (Ref:
AOA)
Multifocal Contact Lens: also known as bifocal lens
that contains two or more viewing zones allowing for one to see distant,
intermediate and near objects.
Myopia (Nearsightedness):
also known as nearsightedness, this inherited and sometimes stress-related
condition occurs when the eyeball is too long or the cornea is too curved.
The result is an inability to see at a distance.
Nearsightedness (Myopia): an inherited,
sometimes stress-related condition that occurs when the eyeball is too
long or the cornea is too curved. The result is an inability to see at a
distance. The medical term for this condition is
myopia.
Non-Specialty Spherical Contact Lens: correct the
most common visual requirements. Most are manufactured by cast molding,
but some are by lathing.
Ophthalmologist: medical doctor (MD) uniquely
trained in all aspects of eye care – medical, surgical, and optical - to
diagnose and treat all disorders of the eye. (Ref: Contact Lens
Council)
Optic Nerve: the two sensory nerves that join the
eyes with the brain.
Optician: A paramedical professional
who manufactures and dispenses eyeglasses and helps in the selection of
frames. The optician may also dispense and/or fit contact lenses,
depending on individual states’ licensing practices.
Optometrist (O.D.): State-licensed health care professional who diagnoses and
treats eye health and vision problems. An OD can prescribe glasses,
contact lenses, engage in low vision rehabilitation and vision therapy,
has the authority to prescribe ophthalmic medications and perform certain
surgical procedures. (Ref: Contact Lens Council)
Oxygen
Permeability: the amount of oxygen diffusing through a given amount of
material in a given amount of time under specified testing conditions.
(Ref: Contact Lens Council)
Peripheral Vision: the ability to see to the
left and the right of direct vision.
Photorefractive Keratotomy (PRK):
a surgical procedure performed using an excimer laser to change
the shape of the cornea to reduce vision problems. (Ref: Contact Lens
Council)
Pink Eye (Conjunctivitis): an inflammation of the
conjunctiva, the tissue that lines the inside of the eyelid and helps keep
the eyelid and eyeball moist. Viruses, bacteria, irritating substances
(shampoo, dirt, smoke, pool chlorine), sexually transmitted diseases
(STDs), or allergens (substances that cause allergies) can all cause
conjunctivitis. Pink eye caused by bacteria, viruses, or STDs can spread
easily from person to person but is not a serious health risk if diagnosed
promptly; allergic conjunctivitis is not contagious. (Ref:
WebMD)
Planned Replacement: see “Replacement
Schedule”
Polymers: a special combination of chemicals that
form the plastics from which contact lenses are made.
Premium
Contact Lens: offer value-added features such as deposit resistance or
ultra-violet protection, exceptional visual results, custom parameters and
colors.
Presbyopia: a condition that occurs as the eye’s
lens grows older and begins to lose some of the elasticity needed to
switch focus between viewing near and far objects. Most people begin to
experience the effects in their mid-forties. (Ref: Contact Lens
Council)
Progressive Lenses: spectacle lenses that feature a
continuous field of vision from up close to far away with no visible
segment lines like traditional bifocal lenses.
Protein
Deposits: a debris that is naturally produced by the eye.
Replacement Schedule: This is a general term
used to refer to the schedule by which one should replace their contact
lenses. In order to achieve comfortable, problem-free lens wear, most eye
care practitioners will recommend lenses be changed every two weeks,
monthly, or quarterly.
Retina: a thin nerve tissue in the
back of the eye. It receives an image from the lens and transforms this
image into electrical impulses that are carried by the optic nerve to the
brain for interpretation. (Ref: Contact Lens Council) The central area of
the retina (the macula) provides the clear, sharp central vision that you
use for focusing on what is in front of you. The rest of the retina
provides side (peripheral) vision. (Ref: WebMD)
Retinal Detachment: occurs when the sensory retina becomes separated
(detached) from the retinal pigment epithelium (RPE) and the wall of the
eye. Fluid from the eye flows into the space between the two layers,
further separating them. (Ref: WebMD)
Retinitis pigmentosa (RP): is a group of inherited
diseases that damage the light-sensitive rods and cones located in the retina,
the back part of our eyes. Rods, which provide side (peripheral) and night vision,
are affected more than the cones that provide color and clear central vision. Signs
of RP usually appear during childhood or adolescence. The first sign is often night
blindness followed by a slow loss of side vision. Over the years, the
disease will cause further loss of side vision. As the disease develops,
people with RP may often bump into chairs and other objects as side vision
worsens and they only see in one direction – straight ahead. They see as
if they are in a tunnel (thus the term tunnel vision).
Rigid Gas Permeable Lens: manufactured from silicon or fluoro-silicon acrylate
base material, these lenses are used for irregular eye prescriptions.
Saline Solution: a salt solution that is
available preserved or preservative free. It is used as a rinse prior to
disinfection.
Snellen Chart: standardized test chart used to
measure visual acuity. Visual acuity is expressed as a fraction (e.g.
20/20) in which the numerator denotes the testing distance and the
denominator indicates the distance at which a person with normal eyesight
can read the letters on the chart. For example, if the smallest letters
that a person being tested can see are on the 20/40 line, it means a
person with normal eyesight can see these same letters at a testing
distance of 40 feet. (Ref: Contact Lens Council)
Soft Contact Lenses: these lenses are made from a flexible plastic know as a
hydrogel. The lens becomes flexible as a result of absorbing approximately
40 to 70% its weight in water.
Specialty Contact Lenses:
corrects visual demands such as astigmatism or special ophthalmic
disorders, also opaque lenses for cosmetic color enhancement. Manufactured
by cast molding, lathing or by FIPS™, CooperVision’s patented combination
of automated lathing and cast molding.
Spherical Aberration:
blurry defect in optical elements that have a spherical surface, caused by
differences in focal length causing light rays to fall on different
locations of the macula preventing achievement of a common focus. (Ref:
Encarta dictionary)
Spherical Contact Lenses: contact lenses
that correct nearsightedness (myopia) and farsightedness
(hyperopia).
Strabismus (crossed eyes): misaligned eyes that
create the inability of one eye to obtain binocular vision with the fellow
eye; usually due to imbalance of the muscles of the eyeball. Eyes may not
only be crossed but could also point outward, upward or downward in the
relaxed position. (Ref: Contact Lens Council; All About Vision)
Tetrafilcon: one of the most durable lens
materials on the market, it produces a thinner, more comfortable lens with
exceptional tear resistance. It also resists build up of protein deposits
on the lens surface and requires little or no enzymatic
cleanings.
Therapeutic Contact Lens: also known as a bandage
lens, this lens is designed to aid in protecting and aiding a sick eye to
heal. This unique lens is frequently combined with precise medication
delivery schedules to heal the eye. (Ref: Contact Lens Council). It’s
usually a large lens which blankets the cornea, retains its moisture and
protects the surface of the cornea. Because the lens is well tolerated, it
provides an effective and often times pain-relieving cover for the
eye.
Tonometry: a standard eye test that determines the
fluid pressure inside the eye. Elevated pressure is a possible sign of
glaucoma. (Ref: Contact Lens Council)
Toric Contact Lens:
designed to correct astigmatism by bearing two different optical powers at
right angles to each other. (Ref: Contact Lens Council)
Trifocal Lens: lenses that correct vision for those with three focal
lengths.
Visual Acuity: expressed as a fraction (e.g.
20/20) in which the numerator denotes the testing distance and the
denominator indicates the distance at which a person with normal eyesight
can read the letters on the chart.

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