Pink Eye | Signs Symptoms | Treatment
A pink eye, technically called conjunctivitis, is the inflammation of the conjunctiva, which is the outer layer covering the eye. It is a very common eye disorder that has several causes. There are also different types of pink eye with different symptoms.
Signs and Symptoms of Pink Eye
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A pink eye
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Itching, burning, stinging, irritation, scratchiness, pain
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Light sensitivity
Not all forms of pink eye are contagious. Pink eye caused by allergens like pollen, dust, smoke etc. are not contagious. Pink eye caused by bacterial or viral infections are highly contagious. These can be spread by coughing, sneezing, shared towels, counter tops and bathrooms.
Pink eye can occur in adults but is more common in children where it is spread rapidly in schools and day care centers. Extra precautions need to be taken in these environments, like frequent hand washing and the use of disinfectant sprays. It is important to educate teachers and scholars about pink eye and the necessary precautions.
Causes of Pink Eye
The way your eyes look and feel will give some indication as to the type of pink eye (conjunctivitis) you have
Allergic conjunctivitis – causes itching, redness and tearing in both eyes. You may also have a runny nose and scratchy throat.
Bacterial conjunctivitis – usually begins in one eye and then affects the other. There is intense mucous discharge form the eye. The eyelids are a little sticky in the morning on awakening. You may have crusting on the eyelids.
Viral conjunctivitis – usually only affects one eye with a watery discharge.
Who is at Risk?
A pink eye can affect anyone but is more common in children as they have more colds and respiratory tract infections which can be the underlying cause.
New born babies are also at risk as they can pick up bacterial infections from the mother during the birth process. A mother who is infected with a sexually transmitted disease like chlamydia or gonorrhea can pass this on to the baby which may show up as pink eye. In these cases antibiotic treatment needs to be given immediately to prevent serious eye damage.
Contact lens wearers are at risk of developing pink eye caused by poor hygiene and over wearing contact lenses.
Can Pink Eye cause Vision Loss?
Most types of pink eye are not serious and are not sight threatening if dealt with in a timely and appropriate manner. However, if you have persistent conjunctivitis, it could be due to a more serious underlying cause that needs to be diagnosed by your doctor.
If untreated, certain types of bacterial conjunctivitis can cause scarring which can permanently affect your vision. In extreme cases of untreated conjunctivitis, the eye may need to be removed as infection spreads to the inside of the eye. This is very rare.
Pink Eye Treatment
Treatment options vary depending on the type of pink eye you have. Antibiotic eye drops may help with bacterial infection but not with viral infections.
Viral conjunctivitis is commonly not treated as it should clear up on its own within a couple of weeks. Artificial tears normally give some relief to the discomfort.
For allergic conjunctivitis, artificial tears may help dilute some of the allergen particles in your tear film. Antihistamine tablets or eye drops provide great relief from symptoms.
For all types of conjunctivitis, warm compressions on the eyes and lubricating eye drops may help the eyes feel better.
Preventing Pink Eye
Bacterial and viral conjunctivitis are caused by airborne sources. So you should try to avoid sharing towels, washcloths etc. in a public environment.
Never share eye drops, eyeliner or mascara. If you have pink eye, discard these items to prevent re-infection.
Never, ever share contact lenses!!
Wash your hands frequently.
For allergic conjunctivitis:
Dust and vacuum often to remove dust and allergens from the home.
Keep windows and doors closed when the pollen count is high.
Stay in a well ventilated area if you are exposed to smoke and fumes.
For contact lens wearers:
- Always stick to the wearing and cleaning schedule given by your optometrist.
- Avoid swimming, bathing or entering a hot tub while wearing your contact lenses. If you do, discard the lenses as soon as possible.
- If you have pink eye, do not wear your contact lenses until your eye has fully recovered.
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Change your solution daily.
- Never share colour contact lenses with your friends.
Remember, pink eye/conjunctivitis is a minor eye infection, but it can sometimes develop into something serious. Because you have no idea of the type of pink eye you have, always consult your optometrist or ophthalmologist before using any eye drop.
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Eye Growths: Pinguecula and Pterygium
Have you been told that you have a pinguecula or a pterygium? These are two very common growths we see on the eye.
Pinguecula
A pinguecula is a tiny yellowish, slightly raised growth found on the white part of the eye just on the border of the coloured part. They are often found in middle aged or older people who spend a lot of time in the sun, but they can also be found in younger people including children who are often outdoors without sunglasses or hats.
In most cases a pinguecula will not cause any problems. However, if they are irritated, it will cause a scratchy itchy feeling in the eye. They may become inflamed and red with exposure to the sun, dust, wind and very dry conditions.
Treatment of a Pinguecula
For mild cases the best form of treatment is protective eyewear whenever you are exposed to the sun. A good pair of wrap-around sunglasses will usually do the trick. Moisture drops can help with the redness and scratchy feeling caused by a pinguecula. Always consult your eye doctor before using an over the counter eye drop.
Surgery is normally recommended when the pinguecula is greatly inflamed and affects your vision or blinking.
Pterygium
A pterygium is a triangular or wedged shaped growth on the white part of the eye. In some cases a pterygium can grow over the cornea and affect your vision. A pterygium is caused by long term exposure to ultraviolet light from the sun.
Just like a pinguecula, a pterygium is normally harmless. It may become red and inflamed on occasion and sometimes they become thick and swollen. This may cause a slight discomfort and become cosmetically unappealing.
In cases where the pterigium becomes very large, it grows onto the cornea and can cause astigmatism.
Treatment of a Pterygium
Lubricating eye drops work well to relieve any redness or discomfort. Consult your eye doctor before using any over the counter eye drop.
Surgery is recommended in cases where the pterygium is growing over the cornea and affecting vision. Unfortunately, a pterygium may re-grow after surgical removal and the re-growth is sometimes worse than the initial growth.
Again, a good pair of wrap-around sunglasses can protect your eyes from all angles.
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Eye Growths: Stye and Chalazion
A stye is a little growth that looks like a pimple on the eyelid. It can be either on the outer or inner eyelid. It can occur at any age and is normally not serious and does not affect vision.
Signs that you are developing a stye
You may notice slight pain, redness, swelling and sensitivity on the affected eyelid. After a day or two, a pimple develops.
You may also get slight watering of the eye, sensitivity to light and a scratchy feeling in the eye.
What Causes a Stye?
A stye is caused by staphylococcal bacteria which is present in the nose. This bacteria is easily transferred when you touch your nose and then your eye.
Everyone has this stye causing bacteria in their body, so we all have the potential of developing a stye. If you do have a stye, you can pass this bacteria onto another person, causing them to develop a stye. So always wash your hands and maintain good hygiene.
Treating a Stye
Most styes heal by themselves within a few days to a week. Applying warm compressions to the eye for 10-15 minutes about 4 times a day, normally speeds up recovery. This will relieve any pain and discomfort. The stye will eventually rupture, drain and heal.
Never pop a stye like a pimple. This normally makes the condition worse. If you continue to develop styes, your ophthalmologist can prescribe an antibiotic to prevent recurrence.
Chalazion
A chalazion is an enlarged blocked oil gland underneath the top or bottom eyelid. At first it may resemble a stye and then becomes a painless hard round bump. The contents of the chalazion are pus and fatty deposits that normally help lubricate the eye.
Treatment of a Chalazion
Most chalazia drain on their own with the help of warm compressions and lid massages.
Occasionally they become larger and may be persist for weeks and even months and become cosmetically unappealing. In this case an ophthalmologist can surgically remove it with a simple in office procedure.
In cases where a chalazion continues to grow in the same area or has a suspicious appearance, a sample will be taken for lab analysis and determine if it is cancerous.
Fortunately most chalazia are harmless.
If you notice any unusual growths in and around the eye area, always consult your optometrist or ophthalmologist as soon as possible.
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Eye Floaters
Eye floaters are those tiny cobweb like spots that float around in our field of vision. In most cases they are harmless and are no need for concern.
When we are born, the vitreous (jelly-like fluid at the back of the eye), has a gel-like consistency. As we get older, this gel starts to dissolve and becomes more liquid. Some undissolved gel-like particles float around in the more watery centre. They may be many shapes and sizes and this is what we refer to as floaters.
These floaters are more noticeable when looking at a white wall or computer screen or at the bright sky. What we are seeing is actually shadows of the floaters reflecting on the retina. Also, they never stay still. They are always moving as your eye moves.
When are Floaters an Emergency?
If you notice a shower of floaters and spots accompanied with flashes of light, you should seek medical attention immediately. This means that the vitreous is pulling away from the retina causing a retinal tear, which could lead to a retinal detachment. Retinal detachments can lead to severe permanent loss of vision. An ophthalmologist needs to be consulted immediately to reattach the retina and prevent blindness.
Light Flashes
When the vitreous pulls against the retina, it causes flashes of light. These flashes may be short lived or continue until the retina is repaired. Sometimes, flashes are also caused after a blow to the head. Some people notice flashes where the light is wavy or jagged, which continues for 20-30 minutes. This is caused by spasm of the blood vessels in the brain. If this is accompanied by a headache, it is a migraine headache. If it is not accompanied by a headache it is called an ophthalmic migraine.
Treatment for Floaters
Most floaters are not serious and require no treatment. They will fade over time and become less bothersome. Eye specialists will only consider removing them if they are so many that they disturb your vision. This is done by a procedure called a vitrectomy. The vitreous gel is totally removed from the eye together with the floaters. The gel is usually replaced with saline.
Remember, the sudden appearance of a significant number of floaters accompanied by flashes of light could indicate a retinal detachment and is a medical emergency which requires immediate treatment.
If you suddenly see floaters, visit your optometrist or ophthalmologist immediately.
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Age and Night Vision Driving
Decreased night vision can be a serious traffic hazard, especially among older motorists who drive after dark.
Unfortunately, the grading of vision screening for driver’s license renewals in our license departments means that large numbers of drivers in this age group may not be seeing their optometrist or ophthalmologist frequently enough to ensure their vision is adequate for safe driving.
A bigger problem is that age-related eye problems, such as cataracts, can develop so slowly that older drivers may be unaware that their vision is declining.
Road Traffic Accidents and Older Drivers
Research has shown that although younger drivers are more likely to cause serious motor vehicle accidents resulting in death, older car drivers are a public health issue, because of age-related declines in vision, cognition and motor function. This makes them more susceptible to car crashes in complex situations that require good visual perception, attention and rapid response.
A typical car driver makes about 20 decisions every kilometre and has less than half a second to react fast enough to avoid an accident. Age affects the 3 essential steps involved in that reaction process: sensing, deciding and acting.
Also, traffic deaths are 3-times more likely to occur at night than during the day.
Why is Ageing and Night Driving a Problem?
As we age, our eyes usually begin to fail long before we notice it.
- Pupils shrink and don’t dilate as much in the dark as we age. This reduces the amount of light entering the eye. The retina receives far less light. This can make older drivers function as though they are wearing sunglasses a night.
- The cornea and lens in the eye become less clear with age, causing light to scatter inside the eye, which increases glare. This makes it harder to see objects on the roads at night.
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An older person may test well in the optometrist’s office but still struggle to focus on the road at night, where lighting is poor and more complex vision tasks are required.
- Older eyes have a higher risk of developing eye diseases like age-related macular degeneration, glaucoma, diabetic retinopathy and cataracts.
These eyesight problems, together or in isolation, may cause a gradual decline in vision and so a driver doesn’t realize that he has become visually impaired.
Despite these many reasons for concern, many older individuals ignore the need for regular eye exams. Taking responsibility for your eyes by having regular eye examinations is the best way to ensure you have the visual abilities needed for safe driving as you get older.
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Presbyopia – Reading Difficulties
Ever heard of presbyopia? If you’re over the age 40, you have probably noticed changes in your vision. Most noticeably, would be changes in your near vision. This is called Presbyopia. It is the normal age-related loss of near focusing ability.
When you develop presbyopia, you may find that you need to hold books, magazines, newspapers, menus and other reading material at arms length in order to focus clearly. Near work, like writing or sewing may cause headaches, eye strain or you may feel tired.
Presbyopia
What Causes Presbyopia?
Presbyopia is caused by an age-related process. It is due to the loss of elasticity and hardening of the natural lens inside your eye. As a result the eye has a harder time focusing up close. It differs from astigmatism, short-sightedness or far-sightedness, which are related to the shape of the eyeball and are caused by genetic and environmental factors.
Treatment Options for Presbyopia
The best way of treating presbyopia is with eyeglasses. Surgery is the other option.
Eyeglasses with bifocal or multifocal (progressive) lenses are the most common correction for presbyopia. Bifocal lenses have 2 focus points:
- The upper portion of the spectacle lens is designed for distance vision,
- The lower portion of the lens is designed for near vision.
The two portions of the eyeglasses are separated by a line.
Multifocal (progressive) lenses have a more gradual vision change between the two prescriptions, with no visible line between them.
Reading glasses are another choice. Unlike bifocals or multifocals, which you would wear all day, reading glasses are worn just during close work.
If you wear contact lenses, your optometrist can prescribe reading glasses, which you wear while your contact lenses are in.
Multifocal contact lenses are also an option. These contact lenses work just as multifocal eyeglasses would, giving you clear vision at all distances.
Monovision is an option where one eye is corrected for distance and the other is corrected for near.
Your optometrist will discuss the best option for you.
The natural lens in your eye continues to change as you get older. Therefore, your presbyopia prescription will need to be increased over time as well. Your optometrist will prescribe a stronger correction for near work as you need it.
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Age-Related Macular Degeneration
Age-related macular degeneration often called ARMD is very common cause of vision loss and blindness among the elderly. It is the degeneration of the macular, which is the area of the retina that gives us sharp central vision which we use when driving, reading etc… Degeneration of the macular, therefore affects our central vision.
There are 2 forms of macular degeneration. Dry (non-neovascular) or wet (neovascular). The term neovascular here means the growth of new abnormal blood vessels in an area. The dry form is more common than the wet form, but the wet form results in much more serious vision loss.
Dry Macular Degeneration (non-neovascular)
Dry ARMD is the early stage of the disease. It is due to the thinning and deterioration of the tissues surrounding the macular. We find yellowish deposits called, drusen, surrounding the macular. These drusen deposits are from the deteriorating macular tissue. Slowly, you start losing your central vision. Over a period of years it can cause severe vision loss.
Studies have shown that vitamins A, C and E, can slow down the progression of dry macular degeneration. Therefore, the use of eye vitamins can reduce the risk of getting macular degeneration.
Wet Macular Degeneration (neovasvular)
Sometimes, dry ARMD will progress to the more advanced and damaging form of the disease, wet ARMD. With wet ARMD new abnormal blood vessels grow underneath the retina. These blood vessels are weak and start to leak blood onto the retinal cells which die off. This causes blind spots in your vision.
The growth of new blood vessels is the body’s way of providing more oxygen and nutrients to the area. Unfortunately, because these blood vessels are abnormal, they leak and cause scarring, leading to severe vision loss.
How do I know if I have Macular Degeneration?
Macular degeneration usually results in a slow painless loss of vision. Symptoms you may notice of macular degeneration are:
- shadowy areas in your central vision
- unusual distorted, fuzzy vision.
Your optometrist or ophthalmologist will be able to detect changes in the macular area before you notice any symptoms. This is done by:
- Retinal exam and,
- Amsler grid.
An Amsler grid is a chart consisting of black lines in a grid pattern.
If changes are detected, a fluorescein angiography will be done to examine the retinal blood vessels around the macular.
Causes and Risk factors for developing Macular Degeneration
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Age
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Hereditary
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Being caucasian (white) and female. ARMD occurs more often in the white population and because they have a lighter eye colour, they are at higher risk from UV damage.
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Obesity and inactivity
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Sun over-exposure
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High blood-pressure
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Smoking
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Drug side-effects
Treatment of Macular Degeneration
There is currently no cure for macular degeneration, but some treatments are available which may slow down the progression of the disease.
The only treatment for the dry form of macular degeneration is nutritional supplements which may prevent its progression to the wet form.
Zinc, lutein, vitamins A, C and E have been shown to reduce the risk of developing macular degeneration and prevent its progression to the wet form.
For wet macular degeneration, treatment is aimed at stopping the growth of the abnormal blood vessels. This is done by the use of drugs injected into the eye. Certain drugs have been shown to improve vision lost to macular degeneration.
So, if you feel you may have symptoms of macular degeneration, or there is a history of the disease in your family, schedule an appointment with your optometrist or ophthalmologist as soon as you can.
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Cataracts of the Eye
A cataract occurs when the eye’s natural lens becomes cloudy. The lens is situated behind the iris (coloured part of the eye). The lens works just as a camera lens works. It focuses light coming through the eye onto the retina. It also changes shape, adjusting focus, allowing us to see clearly from near to far.
As we get older small areas of the lens starts to become cloudy, preventing light from going through to the retina. With time larger areas of the lens become cloudy making it more difficult to see.
Signs and Symptoms of Cataracts
In the initial stages, cataracts may have little effect on your vision. As it grows, you may notice your vision become a little hazy, like looking through a misty window. Sunlight and indoor lighting looks a little brighter than normal. Night driving becomes difficult as oncoming headlights cause a lot of glare. Also, colours are not as bright as they were before.
Some types of cataracts don’t cause any symptoms until it is quite mature. Other cataract types sometimes result in an improvement in your near vision, called “second sight”. This improvement is short lived as your vision deteriorates as the cataract grows.
If you think you have a cataract, visit your optometrist or ophthalmologist for an exam to find out for sure.
Causes of Cataracts
- The most common cause of cataracts is ageing.
- Exposure to ultraviolet light. Optometrists always recommend the use of sunglasses to minimize your eye’s exposure to the sun
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Other types of radiation
- Diabetics. Being diabetic increases your risk of developing cataracts.
- Using steroids
- Eating a lot of salt. Diets high in antioxidants, vitamins A, C and E may slow down cataract development.
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Cigarette smoke and alcohol consumption.
Treatment of Cataracts
In the initial stages a change in your spectacle prescription may improve your vision. As the cataract grows, the only option is surgery. Surgery is normally recommended when the cataract has grown to a point where it significantly impairs your vision and affects your daily life.
Cataract Surgery
Cataract surgery is very successful in restoring your vision and it is relatively painless. During surgery, the surgeon removes the cloudy lens (cataract) and replaces it with an intra ocular lens (artificial lens). If you have cataracts in both eyes the surgery is done one eye at a time, usually a few weeks apart.
After surgery, the eye is covered with a protective shield and within a few hours you will be ready to go home. You will need someone to drive you.
Over the next few weeks you will need to administer eye drops daily and wear sunglasses to protect you from glare. You may have slightly blurry vision which will improve as the eye heals.
During the first few weeks try to avoid any heavy lifting or strenuous activity like exercise. Also, try to avoid swimming pools and hot tubs as they can cause serious eye infections.
Complications during or after cataract surgery is , but sometimes does happen. However, even serious complications can be resolved with appropriate follow up treatments.
Many people consider poor vision an inevitable fact of ageing, but cataract surgery is a simple, relatively painless procedure to regain vision.
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Computer Vision Syndrome
Computer vision syndrome (CVS) most often occurs when the viewing demand of the task exceeds the visual abilities of the computer user. Because computer use is such a visually demanding task, vision problems and computer vision syndrome symptoms are very common. Most studies indicate that computer users report more eye-related problems than non-computer office workers. Studies also show that visual discomfort occurs in 75-90% of computer users.
Computer Vision Syndrome Symptoms
Here are some of the most common symptoms optometry patients will com in complaining of with computer vision syndrome:
- Eyestrain
- Headaches
- Blurred vision (distance and/or near)
- Dry and irritated eyes
- Slow refocusing
- Neck and/or backache
- Light sensitivity
- Double vision
- After images and colour distortion
Reflections and Glare
The most common complaint of computer users is glare. Glare is created by improper lighting in the workspace. The two main sources are from light directly shining into the eyes (direct glare e.g. light from an overhead light) and from reflections from surrounding surfaces (reflected glare e.g. white paper).
Anti-glare filters which fit over the display screen are readily available. It makes it easier to read your screen and helps your productivity. It must be pointed out, however, that anti-glare filters themselves are not necessarily the entire solution to visual stress on computers.
Lighting
Controlling the lighting of the workspace is critical in maintaining proper visual efficiency. Always turn off offending lights. If you notice glare on a screen from a light source, turn it off. Most offices have been designed for paper work and are overly lit for computer use.
Re-orient the work station so that bright lights are not in the field of view. Many people make the mistake of placing their computers right in front of a window, wishing to capitalize on a scenic view. This causes a lot of discomfort glare. The best solution is usually vertical blinds because they can be adjusted to allow for a view while re-directing glare.
Brightness and Contrast
Adjust the display settings on your computer so that the brightness of the screen is about the same size as your work environment. Ideally, your font size should be about 3 times larger than the smallest font size you can see from a normal viewing position. Black text on a white background is the best colour combination for your eyes.
Work Habits
Viewing a computer screen attracts the attention of the viewer more so than any paper object. Because of this, we ‘forget’ to blink. Blinking is an automatic reflex and beyond our conscious efforts. Studies have shown that there is less blinking while viewing a computer screen and this also causes dry eyes. One reason for this is because of the height of the monitor. Because it is in a higher field of view, the eyes are wider open. This creates a wider gap between the eyelids making blinking more of an effort. By lowering the screen, the size of this gap is reduced and allows the lids to blink easier. Also the use of artificial tears can help a great deal. Ask your optometrist which brand he recommends.
When office work still involved typewriters, pencils and paper, there was a great deal of physical activity in the work area. Hands were moving in all directions to insert paper, return the typewriter carriage, grab a pencil or turn a page. Office workers were getting up to make copies, deliver papers to another office, look for carbon paper and other types of physical tasks. With the integration of computers into the workplace, much of these movements are accomplished by the push of a button. Our bodies are designed for movement and should be moved routinely.
This holds especially true for the visual system. Our eyes have many muscles associated with them. If these muscles are ‘stuck’ in the same position for extended periods of time, they will adversely affect vision. Taking visual breaks is a very easy thing to do because they do not involve leaving the desk and do not have to be long in duration.
A micro break consists of simply looking into the distance every 10-15 minutes. This should be done for 15 seconds.
A mini break should be performed every 30 minutes and involves closing the eyes for about 2 minutes.
A maxi break should follow along with your routine work breaks where you get up and move around for at least 15 minutes. This should be done every 2 hours.
This scheme will allow the eyes to change their viewing condition regularly and still allow the worker to produce effectively.
Computer Glasses
Most prescribed eyeglasses are for general purposes: driving, movies, TV, shopping, allowing you to perform a variety of tasks. However, there are also task specific lenses which are made for you to do a specific task. Computer glasses are designed with these types of lenses.
A ‘computer’ prescription is any lens which allows you to see the display screen clearly and comfortably. They do not, however, necessarily allow clear vision at any other distance. There are a number of combination lenses which allow for this type of vision. If your bifocals or multifocals don’t give you much comfort, consider a pair of computer glasses.
Anti-Reflective Coatings
A normal eyeglass lens only allows 92% of light to pass completely through it. The remainder of the light is reflected by the front or back surface. However, a coating applied to the front surface of the lens cancels out this reflection and allows 99% of the light to pass through. This has a double benefit to the general eyeglass wearer. Firstly, it allows your eyes to be more visible to someone looking at you. Secondly, the anti-reflective coating, by allowing more light to pass through them, also makes the view through the lenses more distinct.
This is most noticeable by viewing lights at night, whereby you might normally notice glare around street lights or oncoming headlights. The anti-reflective coating allows lights to pass through the lens without the extra glare or distortion. These lenses make all types of viewing easy on the eyes.
Where to buy Computer Glasses?
Always try to avoid buying over the counter reading glasses for use on a computer. An accurate eye glass prescription is essential if you want to get the full benefits of computer glasses. It’s best to purchase this eyewear from a trained eye care professional like an optometrist.
Before scheduling your appointment, measure the distance from your computer screen to the bridge of your nose. This measurement will help your optometrist prescribe the optimum lens power for your computer glasses.
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Lazy Eye | Amblyopia | Symptoms | Treatment
Today I want to talk a bit about the children’s vision problem of a lazy eye. A lazy eye, technically referred to as amblyopia, means that one eye has not developed normally and always has blurred vision, even with the best correction of glasses or contact lenses.
Lazy eye is caused when the brain favours one eye and refuses to use the other because it cannot use the two eyes together. Because the vision is “turned off”, clear vision does not develop in the lazy eye.
How a Lazy Eye Develops
When we are born with normal vision, we learn to use both eyes together within the first few months of life. Our brains take the pictures from the two eyes and “fuse” it into one image. This is called binocularity.
When we have a lazy eye, our brains did not learn to use the two eyes together. At an early age, these children only use one eye, and their brains “turned off” the images coming in from the other eye. This is called suppression. Because the brain suppressed the lazy eye very early in life, normal vision did not have a chance to develop. So the child has lost the ability to see clearly out of that lazy eye, even with the best pair of prescription glasses or contact lenses. The amount of vision lost depends on how early the brain turned the eye off.
Causes of a Lazy Eye
Refractive Amblyopia This is when one eye is more nearsighted or farsighted than the other, making it difficult for the two eyes to focus together. It starts very early in life. An infant has no way of telling his parents that the one eye does not see as well as the other; so his visual system has to handle the problem by itself. Because it’s difficult to fuse the clear image with the blurry one, the brain suppresses the vision in the blurry eye that’s interfering and just uses the clear one. Long term suppression of the blurry eye causes vision to stop developing. Once discovered, treatment involves prescribing glasses, eye patching and vision therapy. This will establish binocularity and assist development of the poor visual skills that did not have a chance to develop on its own.
Strabismic Amblyopia Strabismus, often called crossed eye or squint, is a condition in which the brain is unable to properly align the two eyes. As a result, one eye may point in or out, up or down. When the two eyes are not pointing in the same place, two different images are being sent to the brain. The brain cannot fuse two different images into one and the result is double vision. The brain is then forced to turn off the vision coming from the misaligned eye to avoid seeing double. The child only uses the straight eye to see and vision in the turned eye does not have a chance to develop.
Treatment for a Lazy Eye
To correct amblyopia, the blurry eye must first be forced to work in order to allow the opportunity for clear vision to develop.
Patching
The child’s clear eye is covered for 2 to 8 hours a day over la long period of time, from 3 months to a year. By forcing the blurry eye to work, its vision improves.
Patching does have some disadvantages. Because the good eye is covered, the child cannot see well and is often frustrated and uncooperative. It becomes difficult to keep the patch on the child. Also, there is a danger of loss of vision in the clear eye when it is covered most of the time for weeks on end.
The gains form patching is not always permanent. While it improves vision, it does not always improve the vision in the lazy eye to 20/20. And once patching is stopped, the improvement in vision can sometimes reverse itself.
Surgery
In cases of strabismus (squint/crossed eye), surgery is sometimes recommended. Unfortunately, eye surgery does nothing to restore normal two-eyed vision, a learned process of the brain. Surgery simply makes the eyes appear straight, a cosmetic fix, and not a visual cure. The child will still suppress the lazy eye after surgery.
Vision Therapy
Vision therapy is highly successful in remediating a lazy eye. It not only corrects the poor vision in the lazy eye, but it also corrects the underlying problem of the brains inability to align and use both eyes together, so the gains are permanent. The patient’s brain is trained to stop suppressing the lazy eye and to fuse the images coming from both eyes for normal two eyed vision. This can be done at any age and is prescribed by a developmental/behavioral optometrist.
The “Critical Stage” for Treatment
Some parents are told that a lazy eye can only be corrected when the child is very young, usually age 6 or under. Some optometrists feel that if treatment is not undertaken during this “critical stage” of development, the amblyopia becomes fixed and untreatable. Parents of older children with lazy eyes are often told that it is too late to treat the problem. New research has found that a lazy eye can be corrected at any age when glasses and patching are combined with vision therapy.
Conclusion
A lazy eye is not easily recognized. A child may not even be aware that one of his eyes is not working with the other. If the eye misalignment is so slight, parents will not be able to tell something is wrong just by looking.
It is extremely important for children to develop equal vision in both eyes in order to succeed in school, sports, or any other activity that requires clear vision, good eye hand coordination, and strong depth perception. Children with untreated amblyopia may have a limited choice of career, and if there is an injury to the one good eye, they could be visually impaired or legally blind for life.
For these reasons, it is extremely important for parents to have their child’s eyes examined by an optometrist or ophthalmologist as early as possible so vision problems can be found and treated. Vision can be tested in infants and very young children, and it is recommended that a child be examined at least by the age of three.
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