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PRESBYOPIA:
New modes of Correction : Multifocal Lasik, Presby-Lasik.
WHAT IS IT?
Presbyopia is the progressive inability of the eye to focus clearly on near objects. What exactly causes this is unknown, but it happens to everyone as a natural part of aging. In order for us to see images clearly, light rays that allow us to see objects enter the eye, where the lens bends and focuses the rays on the retina. The lens changes shape to accommodate the differences in light coming from objects at different distances. The human lens gradually stiffens and loses the ability to change shape. By the time we are in our 40s, the stiffness has progressed to the point that light rays from close objects cannot be properly focused, and we begin to experience blurred vision when we try to do tasks that require up-close focus, such as reading or needlework. The lens continues to stiffen until about age 60, when nearly all elasticity has been lost. Presbyopia eventually affects everyone, even people who are already farsighted (hyperopic) or nearsighted (myopic). Because people who are farsighted already have difficulty focusing on near objects, they may experience presbyopia a little earlier in life. People who are nearsighted may find that their near vision is better when they read without their glasses.
SYMPTOMS
Presbyopia causes the following symptoms:
- Difficulty reading at a previously comfortable distance (words appear blurred)
- Needing to hold reading material or other close objects further away from your eyes to
gain clarity
- Needing brighter light to see clearly (bright light constricts the pupils, which increase the
depth of focus)
- Difficulty reading late at night, or when you are tired or stressed
- Eye discomfort, fatigue or drowsiness when doing close work because of the strain of eye muscles working to change the lens shape.
- Headaches
DIAGNOSIS
Many people over age 40 self-diagnose presbyopia based on their inability to read clearly at a distance that used to be natural and comfortable. Because the condition comes on gradually over many years, most people don't notice small vision changes and delay seeking professional help until the focusing problems interfere with daily life. We will test your vision by having you read text at a distance that is typically comfortable to you. If we diagnose presbyopia, we will determine the extent of the focusing problem. The appropriate lens prescription is made by progressively increasing the magnification power of corrective lenses until the words on the page are clear to you and you are comfortable reading.
EXPECTED DURATION
Presbyopia is irreversible and gets worse as we get older, starting around 40 years of age and plateauing at about age 60.
PREVENTION
Nothing can be done to prevent presbyopia. It is an inevitable part of aging. However, people who do a lot of close visual work (such as working with a computer or intensive reading) may develop presbyopia prematurely. If you do close work, take a 5-minute break every half an hour to relieve strain on the eyes. Allow your eyes to focus on objects at a middle or long distance to give your eyes a rest from close focusing. Be sure to use bright lighting when reading to help your eyes focus.
TREATMENT
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| Monofocal |
Tecnis Multifocal |
MULTIFOCAL LASIK, Near Vision Correction, PRESBY-LASIK
Specially if you have both : a significant distance number and also a seperate near number.
Multifocal LASIK is best suited for all plus numbers even for age 18 or above and for all minus numbers age 35 and above.
Also, See Lasik.
Presbyopia is also treatable with corrective lenses. Glasses are the simplest way to regain near-vision clarity. If you already wear corrective lenses for nearsightedness or farsightedness you may need two sets of prescriptions -- one for distance vision and one for near vision. Glasses may have bifocal lenses, in which the upper portion of the glass is corrective for distance and the lower portion for near vision.
If you don't already wear corrective lenses or you wear contact lenses, you may opt to wear simple reading glasses only when necessary to magnify near objects.
Standard, off-the-rack reading glasses may not be right for everyone. Many people need different amounts of correction in each eye, and therefore require custom glasses. Also, custom glasses are usually made of better materials and are shaped to allow your eyes to focus properly across the full range of the lens.
Note: Because presbyopia continues to get worse as we age, the right magnification this year may not be sufficient next year. Continue to seek out reading clarity; it's not a sign of weakness to have to increase the strength of your glasses.
Contact lenses can also be used to treat presbyopia, although many people find it difficult to adjust to them. Bifocal contact lenses can be made, or you may opt for monovision lenses, in which one eye has a contact lens with a prescription for distance vision, and the other eye has a contact lens for near vision. We will help determine the best course for you.
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DRY EYE:
WHAT IS DRY EYE?
Dry Eye is a collection of symptoms that make up an eye condition that stems from an imbalance in the quantity or quality of tears bathing the eye. These symptoms include dry, red, gritty, and even watery eyes. Often, Dry Eye sufferers report the feeling of something foreign within the eye or eyestrain. Some people do not produce enough tears to keep the eye comfortable.
The balance of tear production and tear loss [through drainage and evaporation] maintains the moisture level in the eyes. When this balance is not sustained, dry spots appear on the surface of the eye and cause irritation.
A healthy eye constantly produces tears that lubricate. Excessive tears occur when a foreign body irritates the eye or when a person cries.
WHAT ARE THE SYMPTOMS OF DRY EYE?
The usual symptoms include:
- Stinging or burning eyes
- Scratchiness
- Stringy mucus in or around the eyes
- Eye irritation from smoke or wind
- Excess tearing
- Difficulty wearing contact lenses
When the eye is irritated, the lacrimal gland produces a large volume of tears which overwhelms the tear drainage system. These excess tears then overflow from your eye.
WHAT CAUSES DRY EYE SYNDROME?
Many different things cause dry eye syndrome. The normal aging of tear glands, as well as specific diseases and disorders, may cause changes in the amount and condition of tears produced.
Decreased sensitivity of the cornea can also lead to insufficient production of tears. Some types of contact lens wear can bring on this lack of sensitivity.
Excessive evaporation of tears can also cause dry eye syndrome. Such evaporation may be caused by meibomitis, which results from infection and inflammation of the meibomian glands in the eyelids. People with unusually large eyes, as well as those who suffer from thyroid disease, may also experience dry eye syndrome caused by excessive evaporation.
Dry EyesDry eye can also result from unusual facial anatomy or irregularities in the cornea, resulting in uneven or inadequate tear coverage of the eye. Some patients suffer from dry eye as a result of medications such as antibiotics, antihistamines, diuretics, and anti-diarrheals, which can dry up the mucous membranes. Hormonal changes can also affect secretions from the tear glands. Since these medications are often necessary, the dry eye condition may have to be tolerated or treated with "artificial tears."
People with dry eye are often more prone to the toxic side effects of eye medications, including artificial tears. Special preservative-free artificial tears may be required.
WHAT IS THE TEAR FILM?
Tears bathe and lubricate the eyes. Each time you blink, a new tear layer forms over the front surface of your eye.
HOW IS DRY EYE DIAGNOSED?
We are able to diagnose dry eye by examining the eyes. Sometimes tests that measure tear production may be necessary. One test, called the Schirmer tear test, involves placing filter-paper strips under the lower eyelids to measure the rate of tear production under various conditions. Another uses a diagnostic dye (fluorescein or Rose Bengal) to look for certain staining patterns.
HOW ARE DRY EYES TREATED?
Depending on the causes, Dry Eye Syndrome can be treated as a temporary problem or a lifelong disease requiring long-term treatment. Either way, tears must be conserved or replaced in order to provide relief.
Adding tears
Artificial tears are probably the most common forms of treatment for Dry Eye Syndrome. These Eye drops are similar to your own tears. They lubricate the eyes and help maintain moisture. Preservative-free eye drops are available if you are sensitive to the preservatives in artificial tears.
Conserving the tears with Punctal Occlusion
Conserving the tears with Punctal Occlusion In cases of persistent Dry Eye symptoms, permanent, reversible closure of the tear duct or punctal occlusion may be the best solution. Punctal occlusion allows you to retain your own, natural tears without the bother or expense of constantly replacing the tear film with artificial tears.
Tears drain out of the eye through a small channel into the nose. We may close these channels either temporarily or permanently. The closure conserves your own tears and makes artificial tears last longer.
A person with dry eye should avoid anything that may cause dryness, such as an overly warm room, hair dryers, wind or a direct fan / air conditioner draft. Smoking is especially bothersome.
Some people with dry eye complain of "scratchy eyes" when they wake up. Using an artificial tear ointment at bedtime can treat this symptom.
WHAT ARE THE WARNING SIGNS AND HOW IS IT DETECTED?
Early signs of dry eye are:
- An occasional burning sensation in the eyes when in areas of low humidity or high pollution.
- A gritty sensation in the eyes, which is persistent and painful.
- Decreased tolerance of contact lenses.
- In extreme cases of dry eye, patients may become unusually sensitive to light, experience severe eye pain, or notice diminished vision.
If early signs persist, make an appointment with us. We need to check for corneal abrasion or infection and begin treatment. Have annual eye exams.
COMPUTER VISION SYNDROME. Tired & Dry eyes.
Many Hours at Your Computer Will Worsen Your Vision - - Unless You Know These Secrets
Computers are now a way of life, something that you cannot do without. As the number of people working on computers continues to grow each year, the number of people encountering temporary vision problems due to computer use also increases. Computers do not harm your eyes, but often cause temporary problems.
Human eyes were meant for hunting and farming and even if we have moved far ahead with technology, our bodies still have to catch up on the metamorphosis from far work to fixed close work.When you look in the distance, your eyes are relatively relaxed and at rest. But while doing near work, such as reading your computer screen, muscles in your eyes have to work harder to keep a clean near focus. These muscles get tired after extended use, resulting in eyestrain, neck pain, blurry near vision, headaches or difficulty changing focus. Dry eyes can also occur because we tend to blink less as we concentrate on our computer screen and keep our eyes wide open when working at the computer, resulting in drying up of the tear film.
Squinting while looking at a computer screen is not only uncomfortable, it can lead to dry eye. This is because squinting causes people to blink less often, and the less you blinked, the more you experience aches, burning and sensations of dryness, irritation and tearing in your eyes.
In fact, squinting even cuts your blink rates in half -- from 15 blinks a minute to 7.5 blinks a minute.Only four blinks per minute
Many reasons can result in this condition.
- Poor position in relation to the computer.
- Lighting that produces glare or reflections, fuzzy images or images that are too dim or too bright;
- Failure to blink often enough to moisten the surface of the eyes;
- Use of glasses that are inappropriate for the user's position and distance from the screen;
- Minor visual defects such as astigmatism that might go unnoticed unless intense computer use exaggerates them.
The following steps can help alleviate your symptoms:
- Lower your computer screen so that the centre of the screen is 4-8 inches below your eye level and at a viewing distance of 20-28 inches.
- Use a document holder placed next to your computer screen. It should be close enough so you don’t have to swing your head back and forth or constantly change your eye focus.
- Change your lighting to lower glare and harsh reflections. Glare filters over your computer screen can also help.
- If you are seated in a draught or near an air vent, try to change your seating or position and direct the draught away from your eyes.
- Low humidity or fumes aggravate a dry eye condition.
- Concentrate on blinking whenever you begin to sense symptoms of dry or irritated eyes.
- Take frequent breaks. Follow the 20-20-20 rule. This simply means every 20 minutes, look away beyond 20 feet and blink 20 times.
- Use artificial tears as recommended by your doctor to re-wet and lubricate your eyes.
While complaints of eye fatigue and discomfort are common among computer users, these symptoms are not caused by the computer screen itself. Computer screens give off little or no harmful radiation (such as x-rays or UV rays). All levels of radiation from computer screens are below levels that can cause eye damage such as cataracts. Fatigue, dry eyes, bad lighting, or how you sit in front of the computer can cause eyestrain. Symptoms of eyestrain include sore or irritated eyes and difficulty focusing. You may also have symptoms of eyestrain if you need glasses or a change in your glasses.
Talk to your ophthalmologist if you suffer from any of these symptoms as you may benefit from a simple prescription
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VITREOUS FLOATERS
WHAT ARE FLOATERS?
Floaters appear as gray or black specks, lines, or "cobwebs", worms, rings or dots in front of the eyes. As the eyes move, the floaters move too. They do not follow your eye movements precisely, as they usually drift when the eyes start or stop moving.
Floaters are caused by clumping of pre-existing vitreous fibers in the eye or bits of material suspended in the vitreous jelly that fills the back of the eye.
The floaters cast shadows on the light sensitive retina. It is actually the shadow of the floater that you see. Floaters may have a variety of causes, some serious, and some not serious at all. Some floaters are red blood cells or blood clots on the surface of the retina or floating in the vitreous. Such blood cells may occur with some retinal tears but do not necessarily indicate a tear. Occasionally, the vitreous can pull on a blood vessel on the surface of the retina and cause bleeding without causing a tear of the retina. Vascular disorders such as diabetic retinopathy and vein occlusion frequently result in bleeding inside the eye.
Rarely, floaters may be inflammatory in origin. Diseases such as pars planitis and uveitis can cause the formation of clumps of white blood cells (cells that the body produces when there is inflammation).
WHAT ARE FLASHES?
Flashes are sensations of light, when no light is really there. They may appear as many tiny bright lights (like "sparklers") or like flashes of lightning.
Flashes occur when the vitreous jelly pulls on or tears the retina. These flashes usually last for only a second or so, but typically occur repeatedly. They may be more obvious with eye movement or in a dark room.
Some people with migraine headaches may experience a different type of flash. These are usually shimmering, jagged lights that are present constantly for a period of ten-fifteen minutes or so. They typically appear in the center of your field of vision, and progress slowly towards the edges of the visual field. A headache that is commonly throbbing, and on one side of the head, may follow the disappearance of the flashes.
Low blood pressure can cause people to see stars or specks of light, particularly if they change position quickly. An example would be standing quickly from a sitting position or rising quickly after stooping or bending over. Pregnancy related high blood pressure (pre-eclampsia) could also cause light flashes.
ARE FLOATERS AND FLASHES SERIOUS?
Many people have floaters. This happens in over 70% of the population as part of the normal aging process. Floaters that you have had for years, and that show little change, are usually not serious. It is the sudden onset of one or more new floaters that may be serious. The onset of flashes may also be serious.
Anyone with flashes or the sudden onset of a new floater (or floaters) needs a dilated fundus examination (looking at the vitreous and retina with specialized equipment after putting drops to enlarge the pupils).
CAN FLASHES AND FLOATERS CAUSE TOTAL BLINDNESS?
No. Floaters cause only a slight blockage of the vision at worst and are usually not detectable by visual testing unless they are very severe.
Importantly, floaters can be related to retinal detachment or a variety of vascular conditions such as diabetic retinopathy, while flashes can be related to retinal tears (breaks) or detachment. These can result in blindness if not treated.
If one eye develops flashes or floaters will the other develop them as well?
It is very common for the same condition to occur in the second eye. For this reason, and because flashes and floaters are sometimes caused by retinal breaks, both eyes should have a dilated fundus exam as soon as possible when flashes or floaters develop in either eye.
WHAT IS THE VITREOUS?
The vitreous is a jelly-like material that fills most of the space inside the eye. As we age, the vitreous often liquefies and may collapse. This is more likely to occur in eyes that are nearsighted (myopia). It can also occur after injuries to the eye or inflammation in the eye.
WHAT IS THE RETINA?
The retina is a thin sheet of light sensitive nerve tissue that lines the inside of the eye. It is the tissue that turns light into an electrical signal to send to the brain. It can be compared to the film in a camera.
WHAT CAN BE DONE ABOUT MY FLOATERS AND FLASHES?
Your flashes are likely to go away on their own within a few days to weeks. This may be true even if you have a retinal tear or detachment! It is therefore important to be examined by an ophthalmologist even if your flashes go away on their own.
Floaters tend to last longer than flashes. If the floaters are due to blood cells, they will typically disappear.Most floaters are condensed vitreous collagen fibers and never completely disappear.
Most people learn to ignore them. Floaters, like flashes, may get better on their own even if a retinal tear or detachment is present. Again, you should be examined even if the floaters seem to be going away.
There is no medicine, eye drop, vitamin, herb, or diet that is beneficial to patients with flashes or floaters.
If light flashes are due to a posterior vitreous separation and no retinal breaks (tears) are found on careful examination with the pupil dilated, no treatment is necessary. If the doctor finds tears, laser or occasionally freezing (cryo) treatment is needed.
If you have a retinal tear or detachment, your doctor will talk to you about the treatment.
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