Glossary of Eye Care and Services at Zeidan

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 shortsighted and the other is longsighted.

Annual Replacement Lenses: conventional contact lenses that are replaced yearly.

Anterior uveitis: 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)

Cataract  is a clouding that develops in the crystalline lens of the eye or in its envelope, varying in degree from slight to complete opacity and obstructing the passage of light. Early in the development of age-related cataract the power of the lens may be increased, causing near-sightedness (myopia), and the gradual yellowing and opacification of the lens may reduce the perception of blue colours.  Cataracts typically progress slowly to cause vision loss and are potentially blinding if untreated. The condition usually affects both the eyes, but almost always one eye is affected earlier than the other- The operation is routine day surgery lasting about 30 minutes and patients normally discharged to normal activities within days.

ChromaGen ™ is the only FDA approved diagnostic system for the management of colour discrimination and reading disorders.: http://www.dyslexia-help.co.uk

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.

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.

Colour Blindness or Colour vision deficiency: A non-specific term for congenital or acquired impairment of colour 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. Colour vision deficiency is not a disease or degenerative condition, though occasionally an acquired colour 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 fibres. 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)

EyeQuest™ are filter lenses designed and researched by Chaaban Zeidan exclusively for use with perception disorders and visual disorientation- successfully used for the treatment and therapy of Glare and light sensitivity, Migraine and Headaches due to prolonged VDU and IT use, Learning disorders and perception , photopsia and other neurological disorders related to visual distress.

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)

Hypertensive retinopathy

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)

IOL-Vip  Intra Ocular lens for Visually Imapired people

Iris: the colored portion of the eye that regulates the amount of light entering the eye by changing the size of the pupil.

Iritis   acute and chronic.  Acute iritis is a type of iritis that can heal independently or with treatment quickly. Chronic iritis can exist for months or years before recovery occurs. Chronic iritis does not respond to treatment as well as acute iritis does. Chronic iritis is also accompanied by a higher risk of serious visual impairment.

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)

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.

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)

Macular degeneration is a medical condition which usually affects older adults that results  in a loss of vision in the center of the visual field (the macula) because of damage to the retina. It occurs in “dry” and “wet” forms. It is a major cause of visual impairment in older adults (>50 years). Macular degeneration can make it difficult or impossible to read or recognize faces, although enough peripheral vision remains to allow other activities of daily life

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)