What is Lazy Eye or Amblyopia?

Lazy eye, or in medical terminology: amblyopia, happens when vision in one eye isn't as sharp as it should be at a certain stage in a person's development.

Lazy eye is typically noticed in infancy and early childhood, where the condition manifests as one eye having reduced visual acuity compared to the other. In some cases, both eyes can fail to develop normal visual acuity.

If detected early, lazy eye can be treated effectively and normal vision restored. If left untreated, however, lazy eye can cause serious visual disability, including legal blindness.

How to test for lazy eye

In many cases, lazy eye can be noticed because the person has crossed eyes (strabismus), so if you notice any misalignment in your child's eyes, then you should schedule an eye testing appointment immediately to consult an optometrist or ophthalmologist.

Young children may not be able to articulate to their parents that something's wrong in their vision. A very simple method for parents to examine their child for signs of lazy eye is by covering and uncovering one eye at a time while he or she is reading or watching TV.

If the child complains when one eye is covered (the 'good' eye), that probably means they're experiencing blurred vision with the uncovered eye.

What causes lazy eye?

There are three types of lazy eye (amblyopia), each with a different cause:

  • Strabismic amblyopia: This is the commonest type of amblyopia and happens due to crossed eyes.
  • Refractive amblyopia: One eye may be near-sighted or far-sighted, while the other eye is not. Another reason for this kind of lazy eye is astigmatism in one eye.
  • Deprivation amblyopia: This type of lazy eye happens when something prevents light from entering in one of the eyes (e.g. a congenital cataract) and impairs normal visual development in that eye.

Treating lazy eye

Lazy eye is normally treated with prescription eyeglasses and contact lenses. In some cases, strabismus surgery may be required to correct misaligned eyes; in other cases an eye patch is applied to the 'good' eye to strengthen the lazy eye's and boost visual development by encouraging children to use it more.

Eye patches for children come in colourful and fun varieties to help them feel more comfortable wearing them and avoid the urge to remove them. There are also special contact lenses and eye drops available that can be used in amblyopia treatment when compliance with eye patching is low.