LAZY EYE (AMBLYOPIA)

What is Amblyopia?

Amblyopia is commonly referred to as ‘lazy eye’. Amblyopia affects a patient's visual acuity and causes poor vision in infancy and early childhood.

Lazy eye can affect only one eye, in which case, the child depends solely on the good eye for vision. Sometimes both eyes are affected.

Complete visual health may not be achieved with prescription lenses and wearing an eye patch.

Who is Affected by Amblyopia or Lazy Eye?

Amblyopia is present in infancy and in early stages of childhood. An average of 2% of the population in developed countries suffer from a lazy eye.

How Does Lazy Eye Occur?

Amblyopia can be traced to development during infancy. Amblyopia is caused by strabismus (squint) in which one eye is able to correctly focus while the other eye possesses a degree of misalignment.

Causes of Amblyopia or Lazy Eye

Amblyopia is caused by a condition known as Strabismus. It develops in infancy and the earliest stages of childhood making it difficult for both eyes to maintain a normal state of alignment.

Lazy eye is caused when the nerves carrying information from the eye to the brain are impaired. Nerve pathway impairment can be caused due to eye problems including:

Strabismic Amblyopia (crossed eye) develops when one eye turns in, out, up or down as opposed to the healthy eye.
Deprivation Amblyopia develops due to the presence of cataract (clouding of the eyes’ lens) or other eye problems that deprive the visual experience.
Refractive Amblyopia develops due to larger or unequal refractive error (inability of the eyes’ lens to focus leading to short-sightedness or long-sightedness).

When the brain receives a blurred image or the wrong image from the defective eye, it gets confused, and over time, favours only the healthy eye. It ignores signals from the weaker eye, which can ultimately lead to poor vision.

Symptoms of Amblyopia or Lazy Eye

The symptoms of Amblyopia or ‘lazy eye’ include:

As others observe

A cross-eyed appearance of the eyes (strabismus),
Visibly misaligned eyes outwards, upwards, downwards or at an angle,
Eyes that periodically wander in or out,
Eyes that do not work in coordination,

As a patient observes

Poor depth perception,
Poor vision in the misaligned eye,
Blurred vision in the affected eye,
Double vision in childhood (strabismus),
Disturbance in toddlers and babies when covering the good eye,
Inability to focus the eye.

Stages of Amblyopia or Lazy Eye

Without corrective treatment for strabismus in which a small angular misalignment is present, the constant strain and difficult adjustment may lead to Amblyopia.

How is Amblyopia or Lazy Eye Treated?

Treatment involves targeting the weak eye and encouraging children to frequently use the weaker eye. The affected eye is examined for common conditions including astigmatism and the eye is treated with the appropriate prescription lenses. Amblyopia is addressed with prescription glasses and wearing a patch.

A patch is recommended for children to wear over the good eye. The healthy eye is covered with a patch encouraging the use of the weaker eye. Although difficult, over time the eye becomes stronger. It can take weeks to months to improve visual acuity in the weaker eye.

Treatment for lazy eye begins in early childhood, and therapy options will depend on the cause and degree of lazy eye affecting your child’s vision.

Eye Drops

Eye drops are an alternative to patches and are instilled daily or twice-weekly into the stronger eye to temporarily blur vision and encourage the patient to use the weaker eye.

Your doctor may suggest other active therapies like puzzles, drawing, or computer games in addition to eye patch or eye drops.

Surgery

Your doctor will recommend surgical repair of the eye muscles if the eyes are crossed or wander apart. Surgery will also be required to correct drooping eyelids or cataract.

Improvement of vision in lazy eye patients may take several weeks to months. Better results and visual improvements are seen if the treatment for lazy eye beings early during childhood.

Treatment may take longer or be less effective if a lazy eye is not diagnosed until pre-teen, teen or adult years.