What is Amblyopia?

Amblyopia, also known as ‘lazy eye’, is a vision development disorder in which one eye fails to achieve proper visual acuity, even with corrective measures, such as glasses. It is typically caused by either disuse of an eye (such as caused by a strabismus (crossed eyes)), or by deprivation of important visual information during development (such as from a misaligned refractive error).

Signs and symptoms of amblyopia

The most common symptom of amblyopia is reduced vision in the affected eye. A person may also experience double vision if binocular vision has been impaired, as well as eye strain, headaches, and fatigue.

Reasons for Developing Amblyopia

The two main causes for amblyopia are strabismus and refractive errors. Strabismus is when the eyes are not aligned correctly, while refractive error is when the eyes do not focus light correctly on the retina. Other causes can include cataracts, ptosis, and corneal aberrations.

Risk Factors

The risks associated with developing amblyopia increase during childhood. Generally, those between the ages of zero and seven are more prone to the condition than older individuals. Additionally, children born prematurely and those of low birth weight have higher chances of developing amblyopia than others.

Diagnosis of Amblyopia

Amblyopia can generally be diagnosed by an eye examination or vision testing, including the “Cover Test”, for which the patient covers one eye at a time and the doctor evaluates for any differences in visual acuity. An optometrist can also conduct a refractive error test, which requires the patient to read alphabet letters from a chart.

Treatment of Amblyopia

  • Prescribing glasses or contact lenses: Depending on the cause, corrective glasses can be prescribed to help align the eyes.
  • Correcting the underlying cause: If strabismus or refractive errors are present, they may need to be corrected before treatment for amblyopia can be successful.
  • Patching: Patching is a common treatment method for amblyopia. By covering the healthy eye, the brain is forced to use the weaker eye in order to see. This forces the eye to become stronger.
  • Eye drops: In some cases, an atropine eye drop may be used to blur the vision of the stronger eye, encouraging the weaker eye to be used and partly used to treat amblyopia.