What is lazy eye syndrome?
Lazy eye syndrome is a disorder of vision most commonly seen in children who develop it as a result of crossed eyes, or strabismus. It can lead to permanent visual impairment, with sight possible through only one eye.
What causes lazy eye syndrome?
When babies are born, they do not have full control over their eye muscles, hence crossed eyes may be a frequent occurrence. However, by 6 months of age, the infant should be able to focus the eyes normally.
- Eyes that do not move smoothly in tandem after about 6 months of age.
- One eye with a tendency to focus inwards, upwards, or outwards while the other follows objects normally.
- Habitual eye rubbing, head tilting, or covering one eye.
- Difficulty with tasks that require estimating distances, such as catching or throwing a ball.
Normal focusing ability may not develop, however, if the muscles that control eye movement are not balanced or aligned properly. As a result, the eyes fail to focus together on an object, and the brain compensates by suppressing the image from one eye. When the brain does not use information from this eye, the eye becomes amblyopic or "lazy."
In rare cases, amblyopia may be caused by severe malnutrition that damages the optic nerve, resulting in permanent optic atrophy.
How is lazy eye syndrome diagnosed and treated?
Consultation with an ophthalmologist is essential for the proper diagnosis and treatment of amblyopia.
Usually, the doctor tries to catch the baby's attention by flashing a shiny object or flashlight into his or her eyes, and then moving the object back and forth and observing the baby's eyes as they follow the object. Then, the doctor alternately covers and uncovers each of the baby's eyes while continuing to note individual eye movement.
What can I do myself?
Because mild amblyopia may occur without noticeable symptoms, all children should be examined by an ophthalmologist before the age of 3. If lazy eye syndrome is diagnosed, parents should rigorously follow the doctor's prescribed treatment.
When should I see my doctor?
Occasional crossed eyes past the age of 6 months, or constantly crossed eyes beyond the age of 3 months, warrant medical attention.
What will the doctor do?
If strabismus and amblyopia are diagnosed, the physician will probably recommend a complete ophthalmological and neurological evaluation to assure that the problem is not caused by some serious ocular or neurological disease. When other problems are ruled out, lazy eye may be diagnosed.
In such cases, a treatment regimen known as orthoptic training is usually prescribed. This training requires the child to do eye exercises and put a patch over the normal eye for at least several hours each day in order to force the brain to process information from the weaker eye.
Never assume that a child will outgrow lazy eye. If treatment is delayed until the child enters school (ages 6 to 7), the problem may no longer be treatable, leaving the youngster with permanent loss of vision in one eye.
If another vision problem such as nearsightedness is present, the child may be given special glasses that are equipped with one corrective lens and one darkened lens to force the brain to depend on the weaker eye.
If muscle weakness is also involved, prescription eye drops that cause blurring in the stronger eye may be used to force reliance on the weaker eye. In rare cases, surgery may be necessary.
When amblyopia is the consequence of malnutrition, it must be treated promptly with vitamin B.
The course of lazy eye syndrome
Lazy eye syndrome usually can be successfully treated and cured if therapy is initiated by the age of 3. However, ophthalmologists usually recommend follow-up checkups until about the age of 10.
If therapy is not initiated early in life, the brain will continue to reject the image from the eye that is not focusing properly, eventually losing the ability to interpret information from that eye. As a result, the child is left with vision in only one eye and a permanent absence of depth perception.
Is lazy eye syndrome dangerous?
If treated promptly, lazy eye syndrome is not dangerous in most cases. However, if treatment is delayed, the condition may become incurable, and vision may be permanently impaired.
What can I do to avoid lazy eye syndrome?
Apart from making sure the child is properly nourished, there isn't much parents can do; some children are simply born with a tendency to develop a lazy eye syndrome.