Amblyopia (Lazy Eye)

Some children may have amblyopia, or "lazy eye". It should be treated as early as possible, or problems may persist into adulthood. Learn more about the causes of this condition and how it can be treated.


Amblyopia, commonly known as "lazy eye", is the reduced vision in one eye that did not develop normal vision during early childhood. The eye with reduced vision generally looks normal and the reduced vision does not improve even with the use of spectacles. If left untreated in early childhood, amblyopia will usually persist into adulthood. It is the most common cause of one eye visual impairment in children and adults.

Lazy Eye Causes

Amblyopia can result from the following conditions:

1. Squint or Misalignment of Eyes

When one eye is looking straight, and the other is looking in another direction, the eyes are said to be misaligned. Due to this misalignment, the vision from the deviating eye is ignored or suppressed. As a result, the part of the brain that receives the vision from the deviating eye does not develop normally, resulting in lazy eye. Eventually, this may lead to a severe reduction of vision in the deviating eye.

2. Different Refractive Powers of the Eyes

Amblyopia may develop if there is a significant difference in the degree of short-sightedness, long-sightedness or astigmatism between the two eyes. When the degree of one eye is much higher than the other eye, there is a higher risk of developing amblyopia.

3. Blurred Vision in One Eye

Blurred vision can cause lazy eye if one eye is unable to form a clear or focused image. This may be due to various conditions such as:
An opaque cornea (the transparent surface layer of the eye)
Cataract — a condition in which the eye’s lens is cloudy
Drooping upper eyelids due to weakness of the muscles that lift the eyelids
Eye trauma or eye surgery

Early Detection

Amblyopia in young children usually goes unnoticed if only one eye is affected, as they may appear to have normal eyesight. It can only be discovered if vision in each eye is tested separately. 

In Singapore, eye screening programmes test child vision before the age of four. If there is any further suspicion of poor vision or signs of eye misalignment, children should be tested by specialists as early as possible.

Early detection of amblyopia is important as it tends to result in more successful amblyopia treatment, especially if detected before the age of four. All children should subsequently still undergo regular eye and vision checks conducted by the family doctor, paediatrician or ophthalmologist.

Amblyopia Treatment

There are a number of lazy eye cures, beginning with treating the underlying conditions causing the lazy eye. This means wearing spectacles for refractive errors or going for eye surgery to treat more complex eye conditions.

The main aim of amblyopia treatment is to stimulate that part of the brain that reads images from the lazy eye — that is, encouraging the lazy eye to work more than the non-lazy eye. Amblyopia treatment needs to be start as early as possible, as once the child is over eight years of age, he/she may not respond well to treatment, resulting in permanently impaired vision.

Amblyopia treatment can be given in two ways:

Patching: this is the main and best form of treatment, where an opaque, adhesive patch is worn over the better eye for weeks to months. This method forces the child to use the weaker eye. If the child has a skin allergy to the adhesive patches, he/she can use a cloth patch that securely wraps around one side of his/her glasses. Opaque taping of glasses or frosted plastic lenses is not recommended as the child can easily peek around the lenses.

Atropine: if the child cannot tolerate eye patches, a drop of drug called atropine is applied to the stronger eye once a day to temporarily blur vision, so that the child will preferentially use the lazy eye. However, this form of treatment may not be suitable for all children.

Amblyopia is not a condition that will go away on its own, and if left untreated, can lead to loss of vision in the lazy eye.

Living with Amblyopia

Common difficulties with traditionally recommended lazy eye treatments is that no child likes to have his good eye patched or impaired. Parents need to explain to affected children the importance of having a lazy eye cured and ensure treatment is implemented as advised by the doctor.

Despite our best efforts however, approximately one to two percent of the population may not respond to lazy eye cures. This occurs when:
There is excessive amblyopic stimuli
The amblyopia is detected too late
The child is unable to cooperate and tolerate, or responds poorly to, lazy eye treatment 

If left untreated or the patient does not respond to treatment, amblyopia can lead to permanent loss of vision in the affected eye. It can also cause loss of three-dimensional (3D) depth perception, or stereopsis, which helps us to perceive the distance of objects. Impaired depth perception makes one unsuitable for some motor functions like driving or playing sports.

In most cases, people living with lazy eye can still go about their daily lives with proper vision in one eye. However, they must ensure that the good eye is protected from harm. They may also be excluded from occupations which require good vision in both eyes.

Read this next:

Amblyopia (Lazy Eye)

 Catalog-Item Reuse

Back to Top