What is Amblyopia?
Amblyopia is reduced vision in an eye that has not received adequate use during early childhood. It is estimated that two to three percent of the general population suffers from this form of visual impairment. If not treated early enough, an amblyopic eye may never develop good vision and may even become functionally blind.
Amblyopia, also known as “lazy eye,” has many causes. Most often, it results from either a misalignment of a child’s eyes, such as crossed eyes, or a difference in image quality between the two eyes (one eye focusing better than the other). In both cases, one eye becomes stronger, suppressing the image of the other eye. If this condition persists, the weaker eye may become useless. With early diagnosis and treatment, however, the sight in this “lazy eye” can be restored. The earlier the treatment, the better the opportunity to reverse the vision loss.
What Treatment is Available?
Before treating amblyopia, it may be necessary to treat first the underlying cause, such as misaligned eyes (strabismus) or poor focusing in one eye.
- GLASSES are commonly prescribed to improve focusing or misalignment of the eyes
- SURGERY may be performed on the eye muscles to straighten the eyes if non surgical means are unsuccessful. Surgery can help in the treatment of Amblyopia by allowing the eyes to work together better. It may be necessary for the surgery to be repeated.
- EYE EXERCISES (orthoptics), a limited form of treatment, may be recommended either before or after surgery to correct faulty visual habits associated with strabismus and to teach comfortable use of the eyes.
Along with correcting the underlying cause of amblyopia, it is necessary to strengthen the vision in the weak eye. This may be done by:
- PATCHING or covering one eye may be required for a period of time ranging from a few weeks to as long as a year. The better seeing eye is patched, forcing the “lazy” one to work thereby strengthening its vision. Regular visits to the eye specialist are necessary to measure improvement in the Amblyopic eye. The greatest improvements come when patching is started before the child is 3 years old. This treatment may be recommended, however, at any time especially before 6 years of age.
- MEDICATION in the form of eye drops or ointment may be used to blur the vision of the good eye in order to force the weaker one to work. This is generally a less successful approach.
Why is Prompt Treatment Important?
The preschool years are critical ones in the development of a child’s vision. By the time a child is 5 or 6, vision is usually at the normal adult level.
Without treatment of amblyopia, the unused eye will lose vision, possibly leading to a permanent reduction of sight. With early detection and treatment before the age of 3, the prospect for the recovery of vision is excellent; approximately 95 percent. After the age of 6, however, vision usually cannot be totally corrected (Utah State Law requires each child entering school for the first time to have a vision test). By the age of 9 or 10, the chances of correcting amblyopia are regarded as slight, although some children in their teens have experienced a reversal in their vision loss.
Proper treatment along with cooperative parents who understand the problem and show patience and love toward the child, usually result in a successful outcome in restoring vision.
Since 80% of what we learn is learned through our vision, it is vital that each child has the opportunity to prepare for life with two good eyes. Many behavior problems in children are due to poor eyesight.
What Are the Signs and Symptoms?
A condition of amblyopia that persists and is untreated until the age of 6 usually will result in some permanent visual impairment. Thus, it is important that parents look for signs of possible eye trouble including: tilting of the head; drifting of an eye when the child is either tired, ill or in bright light; any tendency to close one eye, especially in sunlight; rubbing of the eyes; excessive blinking; holding objects very close to the eyes or favoring one eye. If parents notice such behavior, their child’s vision should be examined professionally.
Vision problems are not uncommon in young children. In fact, preschool vision screening programs show that one child in 20, between the ages of 3 and 5, has some kind of eye problem. A professional eye examination for every child, including those who do not display any signs of eye trouble, is recommended shortly after birth, at 6 months of age, before entering school (age 4 or 5) and periodically throughout the school year. Screening evaluations (in schools, nurseries, etc.) are very useful but are not substitutes for complete professional examinations.