You Can Count on Your Optometrist for Professional Service
Optometrists provide full-service vision care. Just as you would expect your dentist to identify a dental problem and then treat it, your optometrist can identify and treat your vision problems and dispense the eyewear you need. Should any problems arise with your prescription eyewear, your optometrist will provide the best possible solution.
Total Primary Eye Care
Remember, the choice of where you purchase your eyewear is always your own. However, when you make your decision to buy glasses, go to the professional who fully understands your ocular condition, who can obtain the best-quality eyewear quickly and cost-effectively, and who will happily explain to you exactly what you are paying for.
The eye functions very much like a camera. Light enters the eye through the cornea, passes through the pupil, and is focused by the lens onto the retina. For images to be perceived clearly, the light rays must be focused properly on the retina. Otherwise, a blurred or fuzzy image is seen. This condition wherein the images are not properly focused is called an error of refraction (EOR). In general, EORs may cause a person to be nearsighted, farsighted or astigmatic.
Myopia is the medical term for nearsightedness, a condition wherein the eyes can see close objects but are unable to see distant objects clearly. Compared to the normal eye, a myopic eye is longer from front to back. As a result, light is focused in front of the retina, rather than on the retina, resulting in the perception of a blurred image.
In order to have normal, undistorted vision, the cornea should be smooth and spherical or equally curved in all meridians. Some eyes have some degree of astigmatism, or ovalness, to their cornea. Instead of being shaped like a basketball, the astigmatic eye is shaped more like an American football. Therefore, there is distortion or tilting of the images due to asymmetric bending of the light rays. This is sometimes perceived by the individual as a “shadow effect” or a doubling of the image.
Hyperopia is the medical term for farsightedness. It is a misnomer, however, in that people do not necessarily see clearly only for far distance. As opposed to myopia, a hyperopic eye is shorter when compared to a normal eye. This results in light being focused behind the retina causing the perception of a blurred image.
Presbyopia is not an EOR, but rather, an age-related loss of the focusing power for near vision. It usually sets in as one approaches the age of 40 or thereabouts. Normal and farsighted individuals usually require reading glasses once they reach this age. A presbyopic person with a moderate amount of nearsightedness may need only to remove their corrective spectacles for near work or reading.
We recommend that children have their first eye examination by the age of 3.
Clues to Vision Problems in a Child
In a child 1 year or older, also look for these clues:
Kids & Conjunctivitis
You rub and rub your eyes, but they won’t stop itching. When looking in the mirror, they are red and puffy. What’s going on? Do you have a strange sickness? No – you have a common problem called conjunctivitis.
What is Conjunctivitis?
Conjunctivitis is the most common eye problem kids can have. It causes redness, itching, inflammation or swelling, and a white, yellow or greenish gooey liquid to collect in the eyes for about 1 week. Many people know the more common name for conjunctivitis, which is pinkeye. The word pinkeye is used because the white part of the eye and eyelids becomes very red and pink when you have it.
Most people get conjunctivitis in both eyes at the same time. Conjunctivitis usually doesn’t hurt, but the itching is annoying. It feels like you have an eyelash or a speck of dust in your eye and can’t get it out. Your doctor can give you medicine for conjunctivitis.
Adults, especially parents and teachers who spend a lot of time with kids, can get conjunctivitis too. Conjunctivitis lasts a short time and then goes away by itself or after treatment.
How Do I Get Conjunctivitis?
Kids get conjunctivitis for different reasons. Most kids get it from bacteria or viruses. This is called infectious conjunctivitis. Bacteria are smaller than the head of a pin and can only be seen with a powerful microscope. They live on your skin all the time, and you never know it. Most don’t ever bother you, but certain kinds of bacteria can cause infections like conjunctivitis. Sometimes kids get ear infections when they have conjunctivitis, because the same bacteria can cause both problems. Kids also get conjunctivitis because of allergies or because they get something irritating in their eyes.
Conjunctivitis is very easy to catch just through touching. You can become infected by touching hands of a friend who has it if he touched his eyes first. If you then touch your eyes, the infection can spread to you. Washing your hands a lot with hot, soapy water is the best way to not get infected with conjunctivitis.
How Does the Doctor Know That I Have It?
No one knows exactly how many children get conjunctivitis each year, but your doctor treats a lot of kids who have it, and he or she can spot it very quickly. Your doctor will know if you have conjunctivitis by looking carefully at your eyes. He or she will also ask you if your eyes have been red and itchy lately and if you know anyone, like a brother or friend, who has red and itchy eyes too.
Another way your doctor can tell is to look for the liquid coming from your eyes and see if it is different than usual. Finally, your doctor may examine your ears to see if you have an ear infection caused by the same bacteria that can cause conjunctivitis.
What Does the Doctor Say to Do?
The first thing the doctor will do is prescribe a treatment for you, which your parents will get at the pharmacy, the part of the drug store where parents get medicine your doctor has prescribed. This painless treatment will be either eye drops, which you have to put in about four times each day, or an eye ointment, which is given two or three times a day. Babies are usually given the ointment, and kids and adults get the eye drops.
Your parents can help you put the medication in your eyes for about 1 week. It’s important to use whatever the doctor prescribes.
If your eyes are still bothering you, your parents can give you cool or warm packs for your eyes. Sometimes, parents can make you feel better by gently cleaning your eyes with warm water and cotton balls to remove the gooey liquid or crusty stuff. They should be very careful to wash their hands and throw out the towels and cotton balls they use, so they don’t infect themselves or other family members.
The most important thing your doctor will tell you is not to touch your eyes, so no one else in your family or your friends will get conjunctivitis from you. Also make sure to scrub your hands to get rid of bacteria you can’t see, so you don’t spread it to others.
How Can I Keep Myself from Getting It?
There is no way to prevent conjunctivitis, but you can help stop spreading it. Try to keep your hands off your face and eyes and wash your hands often.
What Should I Do if I Think I Have It?
If your eyes are itchy or red, you should tell your parents. Do not wait because conjunctivitis spreads so easily. Your parents will probably call the eye doctor for an appointment.
A number of pathological conditions have been linked to decreases in vitamin and/or nutrient levels within the eye.
The eye is composed of numerous amino acids, enzymes, proteins, minerals, and vitamins, each combining in different concentrations to yield its various components and to maintain normal function. It is therefore important to realize that factors which disturb the balance of these constituents can lead to serious alterations in the function and/or structure of the eye.
A number of pathological conditions have been linked to decreases in vitamin and/or nutrient levels within the eye. Cataracts, or clouding of the lens, which mainly occurs in older individuals, is known to be initiated by oxidative factors, which may in turn lead to the generation of electron stealing compounds known as free-radicals. It is these newly generated by products of metabolism which directly and indirectly rob the crystalline lens of essential vitamins, minerals, and nutrients (vitamins C and E, zinc and carotenoids) which are necessary to maintain lens clarity. Age itself seems to be a contributing factor since it is well established that levels of protective enzymes such as glutathione peroxidase, glutathione reductase, catalase and superoxide dismutase all seem to diminish with increasing age.
In addition to cataract formation, older individuals often are diagnosed with a potentially sight-threating condition affecting the back of their eyes, age-related macular degeneration (ARMD). In this condition, the most vital portion of the retina (macular region), which governs our central vision, undergoes progressive functional, morphological, physiological, and structural changes. The causative agents are theorized to be oxidative stress via light damage and/or a reduction in number or function of pigmented scavenger cells (RPE) responsible for removal (phagocytosis) of metabolic debris from the photoreceptor layer of the retina. A reduction in cell numbers can cause a build-up of heat within the retina thus making it more susceptible to oxidative changes, which leads to a reduction in protective nutrients, enhanced free-radical production, and lipofucin build-up, all of which are detrimental to normal retinal status.
Dry eyes are another common complaint associated with mature persons. The tears are composed of three basic layers (aqueous, lipid and mucin layers) each of which must be present in exact proportions to provide a smooth and comfortable ocular surface. All are rich in proteins, minerals and vitamins. However, as we all age, the relative contribution of each component changes in tear layer nutrients. As a result of these changes, many people report a scratchy or dry sensation in their eyes, or may even complain of fluctuating vision.
The most direct answer to these problems is to replenish or to help revitalize components necessary to maintain optimal ocular functions and health. Specific amino acids, enzymes, minerals, and vitamins may be properly introduced via topical applications or dietary supplementation.
For more information, you can visit www.eyeadvisory.com
How VTDs Can Affect Your Vision
Our goal is to give computer users the knowledge required to help adapt your eyes to this new medium and enhance quality time spent working or playing with a computer.
We’ve all heard about the debilitating effects of repetitive strain injury (RSI) on office workers who fall victim to this painful condition and the resultant losses in productivity. The problem of eye strain from prolonged sessions at video display terminals is broadly similar in its impact on productivity, morale, absenteeism and even health costs, and yet it receives relatively little attention.
This may be because the symptoms of eye strain from video display terminals (VDT) use disappear quite quickly once the sufferer leaves his or her work station or shuts down the terminal. No long-term disability is involved. However, the damaging effects on day-to-day morale, productivity and general well-being in the work place are no less significant.
Eye strain at the computer is a real problem, in both human and economic terms. The symptoms have been collectively described as Computer Vision Syndrome (CVS).
The human visual system evolved primarily for use at far distances, and only secondarily for close-up work. We are simply not properly equipped to comfortably spend long periods staring into VDTs. Our eyes dry out and become sore, our ability to adjust focus slows, vision may blur. Headaches, sore shoulders and pain in the neck may result. We can’t change the basic structure of our bodies, but there is much we can do to minimize the problem of eyestrain.
There are a number of things you can do during your break to help maintain vision comfort.
If you find that your eyes feel hot, dry or gritty while working at your computer workstation, the need for lubricant eye drops may be indicated. Try these eye drops as needed for relief of this problem.
The gritty, burning sensation in the eyes that sometimes accompanies long sessions at the video display terminal can be caused by a number of factors. Firstly, when using a VDT, one tends to blink less than when performing other tasks. That means the eye gets moistened less often.
Additionally, the posture typically adopted when using a VDT contributes to dry eye. When reading text on paper, one’s head is normally tilted down. As a result, the eyelids cover a good portion of the eye. When using a VDT however, one’s head is erect and the eyes are open wider. The evaporation of the tears increases when the eye is opened wider. This results in a higher risk of dry eye.
Dry eye can be particularly bothersome for contact lens wearers and is more likely to be a problem as one gets older.
Other Factors That May Contribute to Dry Eye Include:
Dry eye problems can be reduced by using appropriate ocular lubricants to rewet the eye surface before discomfort arises. This means that the proper tear film quality and quantity must be supplemented periodically for those who suffer from dry eye symptoms. The formulation of the supplement must contribute to the wettability of the eye surface and the tear volume as well as maintaining the proper balance of salts and acidity. Ocular lubricants are classified as an over-the-counter (OTC) preparation. They are available without prescription at most drug stores.
If you are concerned about VDTs or your eyes, talk to us. We are here to help. Please don’t put things off. You can use the handy question form, and we will respond.
Eye symptoms are also common in both airborne and food allergies. Red, itchy eyes are the most common complaint. Hay fever often involves the eyes and nose in a festival of itching and secretion. The eye symptoms are relieved by oral antihistamines or eye drops containing antihistamines or cromoglcyate.
Since hay fever and air pollution produce similar effects, it may be difficult to decide that irritated eyes are caused by allergies. Chemical irritation may look and feel the same as allergies but the mechanism is different and the symptoms do not respond to antihistamines. When the red, itching or burning eye symptoms are chronic, the diagnosis must also include food allergies. Food allergies tend to produce more continuous prolonged eye irritation and are sometimes associated with small growths on the inner surface of the eyelids. Food allergies will almost always cause other symptoms.
Small changes in the cornea with surface eye swelling may be reported as changes in focusing ability or blurring and may be part of a food reaction complex. Blurring of vision is reported frequently and may be associated with migraine headaches. Patients will often complain of blurring of vision as part of a mental fogginess experience. Eye examination usually reveals no abnormality. Sometimes the visual field seems duller or less detailed and with proper diet revision, everything seems sharper and more intensely coloured.
Migraine auras often involve dramatic visual changes with geometric figures appearing in the visual field. Migraine pain often feels like it’s coming from behind an eye and spreads into the forehead and temple. Rarely, a migraine headache is associated with a temporary loss of vision. Pain around and behind the eye is common in migraines. In cluster headaches, a migraine variant, eye pain, reddening and profuse tearing occur.
More serious threats to vision occur with the more serious forms of food allergy, especially food as food allergy turns into autoimmune disease. The major concern is inflammation in the small blood vessels of the retina and in the retina itself. Permanent visual loss can occur; prompt treatment of mysterious retinal inflammation with a food holiday on Alpha ENF (no food problems allowed in) and prednisone may save vision.
Air pollution in the form of chlorofluorocarbons (CFCs) and similar compounds has been responsible for depletion of the stratospheric ozone layer, permitting increased amounts of UV radiation to reach the earth. Excessive exposure to UV from the sun has a potential contributing role in the development of various eye disorders, including age-related cataract, pterygium (growth of tissue on the white of the eye), cancer of the skin around the eye, photokeratitis (sunburn of the cornea), corneal degenerative changes, and age-related macular degeneration. These effects are an important issue for ophthalmologists because of the sensitivity of the eye to UV-A and UV-B light, both of which have the capacity to produce painful conjunctivitis and have been linked to cataracts.
Photochemical smog and its constituents are individually and collectively irritating to the eyes, but current knowledge suggests that permanent eye damage does not result from these forms of air pollution (from Nape Conference Air Pollution).
Indoor Air Quality
All of the indoor air pollutants that bother the nose can also cause eye symptoms. Along with irritation, red burning eyes are the common complaint, sometimes with blurring of vision. Tobacco smoke is the most common culprit at home and in work environments where smoking is permitted.
An ulcer on the cornea causes pain and discomfort in the eye and usually makes the white of the eye turn pink or red. In addition, you can see the ulcer as a whitish patch in the centre or periphery of the cornea (as shown). The vision in the eye is misted over or impaired. This condition needs immediate attention as the bacterial infection can spread extremely rapidly and damage the eye permanently even causing blindness in some cases. These ulcers are more common with extended wear contact lenses (when patients sleep with lenses on for weeks at a time without removal or without regular checkups with their doctor). Call the office if you are concerned at all with any eye discomfort, redness, pain, white lesion on the cornea, or blurred, misty vision.
Symptoms of Glaucoma
Most people who have glaucoma don’t notice any symptoms until they begin to lose some vision. As optic nerve fibers are damaged by glaucoma, small blind spots may begin to develop, usually in the side – or peripheral – vision. Many people don’t notice the blind spot until significant optic nerve damage has already occurred. If the entire nerve is destroyed, blindness results.
One type of glaucoma, acute angle-closure glaucoma, does produce noticeable symptoms. In angle-closure glaucoma, there is a rapid buildup of pressure in the eye (intraocular pressure, known as IOP), which may cause any of the following:
Angle-closure glaucoma is a rare, but serious, form of the disease. If you have any of these symptoms, call your optometrist or ophthalmologist immediately. Unless treated quickly, blindness can result.
Types of Glaucoma
The most common form of glaucoma is open-angle glaucoma. In open-angle glaucoma, the aqueous, or fluid, that normally flows through the pupil into the anterior chamber (the front section of the eye’s interior) cannot get through the trabecular meshwork (the eye’s filtration area) to the normal drainage canals. This causes buildup of pressure in the eye (intraocular pressure, or IOP) which can damage the optic nerve and lead to vision loss.
In acute angle-closure glaucoma there is a sudden increase in intraocular pressure (IOP) due to the buildup of aqueous in the eye.
Acute angle-closure glaucoma is considered an emergency because optic nerve damage and subsequent vision loss can occur within hours of the onset of the problem. Symptoms of this kind of glaucoma can include nausea and vomiting, seeing haloes around light, and pain in the eye.
Chronic angle-closure glaucoma, like open-angle glaucoma, may cause vision damage without symptoms.
Although angle-closure glaucoma is unusual, people of Asian or Inuit ancestry are at higher risk of developing it. As with other forms of glaucoma, age and family history are also risk factors, and the problem seems to occur in older women more often than others.
Both open-angle and angle-closure glaucoma can be primary or secondary. A primary condition is one that cannot be attributed to any known cause. A secondary condition can be traced to another cause, such as previous injury or illness.
“Normal (or low) tension” glaucoma is an unusual and poorly understood form of the disease. In this type of glaucoma, the optic nerve is damaged even though the patient’s intraocular pressure is consistently within a range usually considered normal.
Childhood glaucoma is rare and starts in infancy, childhood or adolescence. Like open-angle glaucoma, there are few, if any, symptoms in the early stage, and blindness can result if it is left untreated. Like most types of glaucoma, this type of glaucoma is thought to have a hereditary component.
Congenital glaucoma is a type of childhood glaucoma that usually appears soon after birth, although it can become apparent later in the first year of life. Unlike other childhood glaucomas, congenital glaucoma often has noticeable signs, including tearing, light sensitivity, and cloudiness of the cornea. This type of glaucoma is more common in boys and can affect one or both eyes.
Your optometrist or ophthalmologist may tell you that you’re a glaucoma suspect if you have one or more risk factors for glaucoma. These may include elevated intraocular pressure (IOP), family history, ethnic background, older age, optic nerve appearance, and other factors.
Elevated IOP is sometimes called ocular hypertension. This means that your IOP is higher than what is considered “normal”. A diagnosis of ocular hypertension does not mean you have glaucoma, but it does mean you’re at increased risk, and should probably have frequent medical eye examinations. Sometimes your optometrist or ophthalmologist will recommend medication to lower your IOP.
Treatment for glaucoma may include medication and/or surgery. Visit www.glaucoma.org for more information.
The retina is subdivided here:
Warning Symptoms of Retinal Tears
Warning Symptoms of Retinal Detachment
Treatment of Retinal Tears or Detachment
There are several ways to repair the retina. It depends on:
The risk if the retina is not treated is it can lead to visual loss or blindness. Treatment of small holes and small tears is an outpatient procedure performed under local anesthetic.
The retina may be repaired using:
Both treatments create a scar. The scar formation that is caused joins the retina to the tissue layer under it (choroid).
Located in the centre of the retina, the sensitive macula provides us with sight in the centre of our field of vision. When we look directly at something, the macula allows us to see the fine details. This sharp, straight-ahead vision is necessary for driving, reading, recognizing faces, and doing close work, such as sewing.
The two common types of macular degeneration are dry and wet. The dry form accounts for 90% of cases and is caused by aging and thinning of the tissues of the macula. It develops slowly and usually causes mild vision loss. People often notice a dimming of vision when they read.
Wet macular degeneration is a much greater threat to vision loss even though it accounts for only 10% of cases. With the wet form of the disease, new blood vessels grow beneath the retina where they leak fluid and blood and can create a large blind spot in the centre of your visual field. If this happens, there will be a marked disturbance of vision.
Although it’s more common for people over 60, it is possible to develop symptoms in your 40s or 50s. Macular degeneration often runs in families. Symptoms can include:
There are new promising treatments for macular degeneration. Visit www.macular-degeneration.org, or you can visit CNIB for more information.
Genetic Testing for Macular Degeneration
Dr. Mayers is pleased to announce that Macula Risk® genetic testing is now being offered for patients with age-related macular degeneration (AMD).
Combined with a comprehensive clinical eye examination, results of the Macula Risk® PGx test determine which patients are at the highest risk of vision loss from AMD and guide us in prescribing the safest, most effective eye vitamin formulations for our patients based on their genetics.
The Age-Related Eye Disease Study (AREDS) has demonstrated that eye vitamins can protect a significant percentage of patients from developing advanced AMD. Recent data suggests, however, that ingredients within the commonly prescribed AREDS formulation, specifically antioxidants and zinc, may be helpful or harmful to some patients based on their genetics.
Information from genetic testing is an important key to prescribing the correct vitamin formulation.
The Macula Risk® PGx test is a simple, painless cheek swab performed in our office. It is generally performed for patients with a diagnosis of early or intermediate AMD.
Diabetes is a disorder caused by decreased production of insulin or by decreased ability to use insulin. Insulin is a hormone produced by the pancreas that is necessary for cells to be able to use blood sugar.
Causes, Incidence, and Risk Factors
The cause of diabetes mellitus is unknown, but heredity and diet are believed to play a role in its development. Diabetes results when the pancreas produces insufficient amounts of insulin to meet the body’s needs. It can also result when the pancreas produces insulin, but the cells are unable to efficiently use it (insulin resistance). Insulin is necessary for blood sugar (glucose) to go from the blood to the inside of the cells, and unless the sugar gets into the cells, the body cannot use it. The excess sugar remains in the blood and is then removed by the kidneys. Symptoms of excessive thirst, frequent urination, and hunger develop. The metabolism of carbohydrates, fats, and proteins is altered.
Diabetes occurs in several forms. The most common types are: Type I, or insulin-dependent diabetes mellitus (IDDM); Type II, or non-insulin-dependent diabetes mellitus (NIDDM); and Gestational Diabetes Mellitus.
Insulin-dependent diabetes mellitus (IDDM or Type I) usually occurs in people before the age of 30 requires insulin injections to live. Risk factors for IDDM include autoimmune disease, viral infections, and a family history of diabetes.
Noninsulin-dependent diabetes mellitus (NIDDM or Type II) usually occurs in severely overweight (obese) adults and rarely requires insulin treatment. Treatment includes diet for diabetics and exercise. Risk factors for Type II are obesity, physiological or emotional stress, pregnancy, certain medications, age over 40, and family history.
Gestational diabetes starts or is first recognized during pregnancy. It usually becomes apparent during the 24th to 28th weeks of pregnancy. In many cases, the blood-glucose level returns to normal after delivery. Risk factors for gestational diabetes are maternal age over 25 years, family history of diabetes, obesity, birth weight over 9 pounds in a previous infant, unexplained death in a previous infant or newborn, congenital malformation in a previous child, and recurrent infections.
Diabetes mellitus affects up to 5% of the population in Canada, almost 1.4 million people.
Blurred vision is the loss of visual acuity or sharpness resulting in unclear visual details. Vision loss is the inability to perceive visual stimuli. Blind spots are apparent dark “holes” in the visual field in which nothing can be seen. An enlarging blind spot is growth in the size of a blind spot that is readily apparent to the individual.
Call Your Optometrist if:
What to Expect at your Optometrist’s Office
The medical history will be obtained and an examination performed.
Medical history questions documenting the vision abnormalities in detail may include:
Have you had any of the following in the last few weeks to months?
Additional Important Information
The examination will include an eye examination. The Optometrist will check vision, eye movements, pupils, back of the eye, and eye pressure when indicated.
Diagnostic tests that may be performed include:
Surgery will be recommended for some conditions (such as cataracts or muscle problems). Diabetics must control their blood-sugar level. Other treatments depend on the cause.
Safety measures may be necessary to help a person with vision abnormalities. For example, it may be helpful to increase the amount of light in a room.
Loss of visual acuity, changes in vision, blurriness or decreased light perception should always be evaluated as soon as possible by a medical professional. Changes may represent primary eye disease, aging, eye trauma, or a generalized (systemic) illness. Whatever the cause, visual changes should never be ignored. Decreased vision is a significant threat to the quality of life. Professional help is always indicated, but which professional to see is often a question.
Causes, Incidence and Risk Factors
The lens of an eye is normally clear. If the lens becomes cloudy or is opacified it is called a cataract. Cataracts may be present at or shortly after birth in which case they are called congenital cataracts. Adult cataract develops with advancing age, tends to run in families, and the appearance may be accelerated by environmental factors. Cataract may develop at any time throughout life following an eye injury in which the capsule of the lens is damaged. Cataract may also develop in response to metabolic diseases such as diabetes.
Congenital cataracts are cataracts which are present from birth (or appear shortly after). They may be familial (autosomal dominant inheritance), or they may be caused by congenital infections such as rubella, or associated with metabolic disorders such as galactosemic. Risk factors include inherited metabolic diseases, a family history of cataract, and maternal viral infection.
Adult cataract is generally associated with aging. It develops slowly and painlessly with a gradual loss of vision. Visual problems may be heralded by difficulty seeing at night, halos around lights or glare when looking at lights, and finally, decreased visual acuity, even in daylight.
Adult cataracts are classified as immature, mature, or hypermature. A lens that has some remaining clear areas is referred to as an immature cataract. A mature cataract is completely opaque; a hypermature cataract has a liquefied surface that leaks through the capsule and may cause inflammation.
Most people develop some clouding of the lens after the age of 60. About 50 percent of Canadians ages 65 to 74 have cataract and about 70 percent of those ages 75 and over have it. Most people with cataract have it in both eyes, although one eye may be worse than the other. Many people with cataract don’t even know they have it.
Other factors that may contribute to cataract development are low serum calcium levels, diabetes, long-term use of corticosteroids, and other inflammatory and metabolic disorders. Other causes include trauma, radiation exposure, and excessive exposure to ultraviolet light (sunlight). In many cases, the cause of cataract is unknown.
Cataract treatment is done simply to improve vision. For some people changing their glasses, getting stronger bifocals, or using a magnifying lens is helpful enough. Others choose to have cataract surgery.
If you are not bothered by a cataract, then treatment is usually not necessary. On occasion, there may be an additional eye problem that the doctor needs to see or treat and the cataract impairs the doctors view. In these cases, cataract surgery may be required to allow proper treatment of the other eye problem.
Cataract surgery consists of removing the lens of the eye and replacing it with an artificial one. Your doctor will discuss the options with you and together you will decide which type of removal and lens replacement is best for you.
There are 3 different types of surgery that can be used to remove lenses that have a cataract.
Extracapsular surgery consists of surgically removing the lens, but leaving the back half of the capsule (the outer covering of the lens) intact.
Phacoemulsification is done by softening the lens with sound waves and then removing it through a needle. The back half of the lens capsule is left behind.
Intracapsular surgery involves surgically removing the entire lens, including the capsule. This is done very rarely.
People who have cataract surgery usually get an artificial lens at the same time. The artificial lens is a plastic disc called and intraocular lens. It is placed in the lens capsule inside the eye.
Other options include contact lenses and cataract glasses. You and your doctor will decide which choice is best for you.
Surgery can be done in an outpatient center or hospital, and you can leave when your doctor says you are fit to go. Most people do not need to stay overnight in a hospital. You will need a friend or family member to take you home and someone will need to stay with you for a day or two to help you follow your doctor’s instructions.
It takes a few months for an eye to heal totally so your doctor should check your progress periodically and make sure you have the care you need until your eye fully recovers.
Very frequently associated with nearsightedness is an oval cross section to the corneal surface, called astigmatism. Imagine looking through a lens that was distorted to provide more focus vertically than horizontally. This is the case with astigmatism, (though it can be along any axis, it does not have to be vertically) with your cornea functioning as the lens.
Think of the normal cornea as being round, or spherical, with both horizontal and vertical curvature the same (two arrow diagram above).
Think of astigmatism as if the cornea was pinched along the single arrow, or A. The circular ring reflection hits a plane of the cornea at the flatter curvature B before it does the steeper curvature at A that is further down – closer to the corneal base before reflecting onto the cornea there (further from the surface before reflected surface reached because it is pinched, or steeper vertically and the ring reflection hits a point further down). This creates an OVAL reflection – and visually a “streak effect”. (The reflection has a smaller chord diameter along A (further away) and larger at B (closer)). This cornea would be described as having + cylinder at 90 degrees, or – cylinder at 180 degrees.
Every oval has a short and long diameter 90 degrees away from each other. The axis of the short diameter, known as the treatment axis of the positive astigmatism could be vertical, or any other direction over the 360 degree surface. A prescription written may look like this: -4.00 -2.00 x 90.