Amblyopia is an eye condition that develops during childhood in which the vision in one eye is weaker than in the other. It occurs even if the child seems to have no other ocular (eye) problems. Because amblyopia can have serious, permanent effects on your child, it is important that he or she have regular vision tests.
The most common cause of amblyopia is a major difference in the focusing powers of the two eyes. For example, large differences between the two eyes in astigmatism (irregular shape of the eye) or farsightedness can cause amblyopia. The brain will favor seeing out of the eye that provides a clearer and sharper image and will neglect the other image, which can cause the vision in the weaker eye to get worse.
Another cause of amblyopia is a misalignment (poor positioning) of the eyes (strabismus); for instance, if the eyes are crossed or drift apart. If this happens, the brain tends to favor using the eye that is more frequently aligned (positioned) and ignore the other eye, which leads to a decline in vision.
Other causes of amblyopia arise from anything that is blocking the visual axis (line of vision) of an eye. For example, a cataract (a clouding of the lens), intraocular tumor, or an injury that causes bleeding into the eye or scarring of the front surface (cornea) of the eye may blur the visual axis and lead the brain to favor the stronger eye.
Amblyopia can also develop in both eyes if both images are blurry due to any cause. Cloudy vision in both eyes can interfere with the visual stimulation to the brain, which can lead to a permanent weakening in eyesight.
Your child’s pediatrician or the vision program at school will check three features of your child’s eye health:
If there seems to be a problem (something blocking the light, unequal vision, or concern with movement), the pediatrician or school nurse might recommend a visit to an eye specialist such as a pediatric ophthalmologist.
The eye specialist will:
Sometimes problems can be found before the child develops amblyopia. In most children with amblyopia, however, the vision has already started to get worse by the time they visit the doctor.
There are several types of treatment for amblyopia. Treatment should be started as soon as possible after the diagnosis, while the child is still young and the connections between the brain and the eye are still developing.
Treatment works best in children under 6 years old, and maybe up to around 10 years old. Different treatment will be recommended based on the cause of your child’s amblyopia. Some of the most common treatments include the following:
Your doctor will discuss with you what treatment is most appropriate for your child.
What is the outlook for children with amblyopia?
When eye problems like those described above are found and managed early, most children regain normal vision in the amblyopic eye. However, amblyopia in older children is more difficult to treat. In some cases, if the amblyopia is severe before treatment is started, vision may not completely improve.
If too much vision is lost in the eye with amblyopia, it might be impossible to get it all back, but treatment should be continued until no more improvement can be made.
It is very important to follow your doctor’s advice about treatment. It can be challenging to convince a child to wear an eye patch every day. With the use of atropine as another method of treatment, more and more children with amblyopia can be successfully treated.
When should children have eye examinations?
Amblyopia often starts before there is any obvious sign that something is wrong. This is why babies and young children need to have their eyes checked at regularly scheduled appointments with the doctor.
The American Academy of Ophthalmology recommends that children have eye examinations at the following times:
If you are concerned that your child may be suffering from or developing “lazy eye,” have him or her examined right away. Children whose family members have amblyopia are at a higher risk for developing it themselves.
What is a cataract?
Cataract is clouding of the normally clear lens of the eye. This clouding can weaken vision. The amount and pattern of cloudiness in the lens vary from person to person.
Cataract is a normal aging change of the eye. Cataracts often form slowly and cause few symptoms. When symptoms are present, they can include:
The eye functions much like a camera. Light rays enter through the front of the eye, passing through the cornea, the pupil, and the aqueous humor (transparent fluid in the front of the eye) onto the lens. The lens then bends light rays to focus objects onto the retina in the back of the eye. From there, the retina, the optic nerve, and the brain process the images and form vision.
Cataracts occur when there is a buildup of protein in the lens. The protein makes the lens cloudy and prevents light from passing through, which causes some loss of vision.
Cataracts can also be caused by:
Other factors that increase the risk of developing cataracts include cigarette smoke, air pollution, and heavy alcohol use.
A thorough eye examination by your eye doctor (ophthalmologist) can identify a cataract, as well as any other conditions that may be causing blurred vision.
The eye exam will tell your doctor how much vision you have lost. If there is not a great deal of vision loss, your doctor may prescribe eyeglasses (including bifocals), magnification device s, contacts, or other visual aids.
In the early stages of cataract development, vision may be improved simply by a change in glasses prescription. In time, as the cataract increases, blurred vision and other symptoms will not be relieved by glasses; therefore, the patient will need surgery to restore useful vision.
When should surgery be performed?
Cataract surgery should be considered when the cataract causes enough loss of vision to interfere with daily activities that are important to the patient, such as reading or driving, or recreational activities such as foorball, golf or tennis.
Occasionally, cataract surgery will be necessary to evaluate and treat other eye conditions, such as diabetic or age-related changes in the retina. Your ophthalmologist can help you with the decision about surgery under these circumstances.
How is cataract surgery performed?
Cataract surgery is performed on an outpatient basis with local anesthesia (the patient is awake but does not feel the procedure). During the surgery, the clouded lens of the eye is broken up with high-frequency sound waves or ultrasound and then suctioned from the eye by a process called phacoemulsification. The clouded lens is then replaced with a clear, plastic intraocular lens implant in order to restore vision. The power of the manmade lens is selected to fit your eye and to help restore normal vision.
Cataracts in both eyes are not removed at the same time, but will require separate surgeries.
A laser, known as the femtosecond laser, can be used for cataract surgery. This may allow for more precise outcomes but it is not popular.
What can I expect after surgery?
After surgery, it is normal to feel itching and some mild discomfort. Your doctor may recommend that you take a pain reliever, like Tylenol. You may also have temporary fluid discharge from your eye, and be sensitive to light for a short time after the procedure. For a few weeks after surgery, you will need to use eye drops to aid healing, prevent infection, and control the pressure inside your eye. Strenuous activity, such as heavy lifting or activities that might lead to risk of a blow to the eye, should be avoided for several weeks. Normal non-strenuous activities, including bending, lifting, reading, and driving, can be resumed the day after surgery.
How soon will my vision improve after surgery?
Most patients will have good vision in the operated eye about a week after surgery. You may still need to wear glasses after cataract surgery.
Is cataract surgery safe?
Nearly 98% of all cataract surgeries are performed each year without serious complications. Though this type of surgery is very safe, you should discuss the risks with your ophthalmologist.
How successful is cataract surgery with lens implantation?
Cataract surgery with lens implantation is the most frequently performed surgery (millions each year). More than nine out of 10 people who have cataract surgery regain excellent vision.
What are the long-term effects of cataract surgery?
Lens implants are permanent and ordinarily do not need to be replaced. They are good for the life of the patient.
In a minority of patients, a clouding occurs on the lens capsule months or years after surgery. In this case, an office procedure using a laser can open a small hole to restore normal vision.
Will insurance cover the cost of the procedure?
Cataract surgery is covered by most of the insurance companies.
Can cataracts be prevented?
Because the exact cause of cataracts is uncertain, there is no proven method to prevent them from forming.
What are dry eyes?
The eye depends on the presence of a tear film to provide constant moisture and lubrication to maintain vision and comfort. Tears are a combination of:
These components are secreted by special glands located around the eye. When there is an imbalance or deficiency in this tear system, or when the tears evaporate too quickly, a person may experience dry eye.
When tears do not lubricate the eye enough, you may have the following in your eye:
Sometimes, a person with dry eye will have excess tears running down the cheeks, which may seem confusing. This happens when the eye isn’t getting enough lubrication. The eye sends a distress signal through the nervous system for more lubrication. In response, the eye is flooded with emergency tears.
However, these tears are mostly water and do not have the lubricating qualities or the rich makeup of normal tears. They will wash dirt away from the eye, but they will not coat the eye surface properly. In addition, because these emergency tears tend to arrive too late, the eye needs to regenerate and restore itself, and treatment is necessary.
The majority of patients with dry eye have chronic inflammation (swelling) in the tear glands (lacrimal glands) that line the eyelid and in the conjunctiva (the thin lining on the inside of the eyelids and the front part of the eye). Just like inflammation in a knee, the lungs, or liver, this chronic inflammation can permanently damage the tear gland tissue to the point that treatment becomes ineffective.
In addition to an imbalance in the tear-flow system of the eye, dry eye can be caused by the drying out of the tear film. This can be made worse by dry air created by air conditioning, heat, or other environmental conditions. Many patients also have ocular rosacea (meibomian gland dysfunction), an abnormality of the glands on the edge of the eyelid (meibomian glands) that are supposed to produce the oil to prevent evaporation of the tears. When a patient has both dry eye and ocular rosacea, not only does he or she produce too few tears, but the tears he or she does make evaporate too quickly.
You should discuss treatment options with an ophthalmologist (eye doctor). In some cases, dry eye is caused by another disease or condition, like rheumatoid arthritis or systemic lupus erythematosus. If this is the case, the systemic disease should also be treated in order to relieve the dry eyes.
Here are some common treatments for dry eyes:
Topical Cyclosporine A Eye Drops (Restasis®)
These are given two to four times a day in each eye to treat the underlying inflammation in the tear glands so they produce more tears and better quality tears. It typically takes one to four months before the cyclosporine A drops reduce symptoms and signs of dry eye. These drops have been found to be safe; the main side effect is stinging upon application, which usually gets better with continued treatment.
Sometimes the ophthalmologist will also treat with corticosteroid drops for two weeks just before the cyclosporine A to speed up the treatment and reduce stinging caused by the cyclosporine A. The corticosteroids cannot be taken long-term due to the risk that they will induce cataracts and glaucoma.
Artificial Teardrops and Ointments (The most common Treatment)
The use of artificial teardrops is a palliative (soothing) treatment that helps symptoms for a few minutes but does not treat the underlying cause of the dry eye disease. Artificial teardrops are available over the counter. No one drop works for everyone, so you might have to experiment to find the drop that works for you. If you have chronic (long-lasting) dry eye, it is important to use the drops even when your eyes feel fine, to keep them lubricated.
If your eyes dry out while you sleep, you can use a thicker lubricant, such as an ointment, at night. If you have ocular rosacea associated with dry eye, then newer artificial tears contain lipid to help prevent tear evaporation. If you take artificial tears four or more times a day, you should use non-preserved artificial tears, since preservatives will likely worsen your condition.
Temporary Punctal Occlusion
Sometimes it is necessary to close the ducts that drain tears off the eye. This is done via a painless procedure where a plug is inserted into the tear drain of the lower eyelid. The plug will dissolve quickly. This is a temporary procedure, done to determine whether permanent plugs will help reduce symptoms and signs.
Permanent Punctal Occlusion
If temporary plugging of the tear drains works well or plugging is thought to be important for the health of the eye, then silicone plugs may be used. (Some physicians will go directly to silicone plugs without using temporary punctual occlusion.)
The permanent plugs will hold tears around the eyes as long as they are in place. They can be removed. Rarely, the plugs may come out on their own or move down the tear drain. Many patients find that the plugs improve comfort and reduce the need for artificial tears.
If needed, the ducts that drain tears into the nose can be permanently closed to allow more tears to remain around the eye. This is done with local anesthetic on an outpatient basis. Cyclosporine A drops should always be tried for at least 6 months before permanent punctal occlusion to ensure the patient doesn’t have tears running down the face (epiphora) when the dry eye inflammation is treated and the glands produce more tears.
Autologous Serum Drops
In severe cases of dry eye, artificial tears made from the patient’s own serum can be prepared and given 6 to 8 times a day in both eyes. This treatment, although often effective, is expensive and is not covered by health insurance programs.
On your own, you can take these steps:
Symptoms can be greatly improved by these treatment options.
Low vision is the loss of sight that is not correctable with prescription eyeglasses, contact lenses, or surgery. This type of vision loss does not include complete blindness, because there is still some sight and it can sometimes be improved with the use of visual aids.
Low vision includes different degrees of sight loss, from blind spots, poor night vision, and problems with glare to an almost complete loss of sight.
There are two defined categories of low vision:
The ratio measurement of vision describes visual acuity, or the sharpness of vision, at 6 meters (20 feet) from an object. For example, having 20/70 vision means that you must be at 6 meters (20 feet) to see what a person with normal vision can see at 21 meters (70 feet).
Anyone can be affected by low vision because it results from a variety of conditions and injuries. Because of age-related disorders like macular degeneration and glaucoma, low vision is more common in adults over age 45 and even more common in adults over age 75. For example, one in six adults over age 45 has low vision; one in four adults over age 75 has low vision.
The most common types of low vision include:
What causes low vision?
There may be one or more causes of low vision. These are usually the result of disorders or injuries affecting the eye or a disorder such as diabetes that affects the entire body. Some of the most common causes of low vision include age-related macular degeneration, diabetes, and glaucoma. Low vision may also result from cancer of the eye, albinism, brain injury, or inherited disorders of the eye including retinitis pigmentosa. If you have these disorders or are at risk for them, you are also at greater risk for low vision.
How is low vision diagnosed?
An eye exam by your eye care specialist can diagnose low vision. You should make an appointment with your eye doctor if your vision difficulties are preventing you from daily activities like travel, cooking, work, and school. The tests the eye doctor will perform include the use of lighting, magnifiers, and special charts to help test visual acuity, depth perception, and visual field.
Can low vision be treated?
Some sight disorders, like diabetic retinopathy, can be treated to restore or maintain vision. When this is not possible, low vision is permanent. However, many people with low vision find visual aids helpful. Popular low vision aids include:
Some patients with retinitis pigmentosa who have no useful vision may be eligible for the Argus® II retinal prosthesis. This device partially restores vision to patients who have lost their sight. In some patients, the restored vision allows for them to independently navigate through doorways, sidewalks, sort light and dark colored laundry, or even read large letters.
Non-optical aids designed for people with low vision are also very helpful. Some popular non-optical devices include:
Visual aids improve both sight and the quality of life for many people. Talk to your doctor about where to purchase visual aids.
Can low vision be prevented?
Low vision may be preventable for patients with diabetes, and some patients with macular degeneration and glaucoma may be treated to prevent the further vision loss.
What is night blindness?
Night blindness (nyctalopia) is the inability to see well at night or in poor light. It is not a disease in itself, but rather a symptom of an underlying problem, usually a retina problem. It is common for patients who are myopic to have some difficulties with night vision, but this is not due to retinal disease, but rather to optical issues.
What causes night blindness?
Night blindness has many causes, including:
To determine what is causing night blindness, an eye doctor will perform a thorough eye exam and may order any of a number of specialized exams.
How is night blindness treated?
Treatment for night blindness will depend upon its cause. Treatment may be as simple as getting a new eyeglass prescription or switching glaucoma medications, or it may require surgery if the night blindness is caused by cataracts.
If a retinal disease is discovered, the treatment will depend on the type of the disease and will require additional investigation by a retina specialist.
Presbyopia And Your Eyes
Presbyopia is part of the natural aging process of the eye, and can be easily corrected. Technically, presbyopia is the loss of the eye’s ability to change its focus to see objects that are near. It is not a disease. It’s as natural as wrinkles, and it affects everybody at some point in life. Presbyopia generally starts to appear around age 40.
Presbyopia is often confused with farsightedness, but the two are different. Presbyopia occurs when the eye’s lens loses flexibility. Farsightedness occurs as a result of the shape of the eyeball, which causes light rays to bend incorrectly once they have entered the eye.
What are the symptoms of presbyopia?
Symptoms of presbyopia include:
How is presbyopia diagnosed?
An eye doctor can diagnose presbyopia by a thorough eye exam.
How is presbyopia treated?
Presbyopia cannot be cured. Instead, prescription glasses, contact lens, reading glasses, progressive addition lenses, or bifocals can help correct the effects of presbyopia.
Bifocals are often prescribed for presbyopia. Bifocals are eyeglasses that have two different prescriptions in one spectacle lens. The main part of the lens contains a prescription for nearsightedness or farsightedness, while the lower portion of the lens holds a stronger prescription to help a person see objects up close.
Progressive addition lenses are similar to bifocals, but have a more gradual shift between the two prescriptions.
Contact lenses that are used to treat presbyopia include multifocal lenses, which come in soft or gas permeable versions, and monovision lens, in which one eye wears a lens that aids in seeing objects at a distance, while the other has a lens that aids in near vision.
For patients who are having cataract surgery, there are new lens implants that offer partial correction for presbyopia as well as correcting for distance vision.
Protecting Your Child's Vision
There are many things you can do to keep your child’s eyes healthy and seeing clearly from birth through the teen years.
Here are some tips to help your baby develop healthy visual skills.
Make sure your baby is following moving objects with his or her eyes and developing eye-hand coordination. If he or she seems delayed, talk to your child’s doctor.
As your baby grows into an active child, continue to encourage good visual skills by providing visually stimulating toys that will improve motor and eye-hand coordination skills. Some good examples are:
How can I protect my child's sight?
How often should children's eyes be checked?
There are no strict guidelines. However, a detailed examination by an ophthalmologist, preferably a pediatric ophthalmologist, in the first year of life and another one between the ages of three and four is recommended. Additional exams are administered if screenings at the pediatrician show any ocular misalignment or visual difficulties. Children with siblings or close relatives with significant eye problems should be examined early and repeatedly by a pediatric ophthalmologist.
What do I do in an emergency?
If your child gets something in his or her eye and you don’t know what it is (or if there is alkaline in it – most household products will so indicate alkaline on the label), flush your child’s eye for at least 20 minutes and have someone call for medical help or the local poison control center. Do not stop flushing your child’s eye until medical help arrives unless instructed otherwise.
If your child is hit in the eye with a blunt object, examine the eye closely. If you see bleeding, or cannot open the child’s eyelids or observe his or her pupils, you should seek immediate medical attention. If your child continues to be in pain, constantly rubs his or her injured eye or complains of blurry or double vision, call the doctor. In the meantime, cover your child’s injured eye with a cold pack for 15 minutes every hour or so. If you are using an ice pack, wrap it in a moistened cloth so the eye does not become damaged from freezing.
If your child’s eye is injured with a sharp object, cover the eye with a shield (the cutout bottom of foam cup would do) as you would above and seek immediate medical attention. DO NOT press on the eyelids. If the sharp object is still in the child’s eye, DO NOT remove it. Instead, cover the eye and call 9-9-9.