Row of eyes

Amblyopia is a condition when one eye is unable to see as well as the other eye, even with glasses correction. This is also loosely called ‘lazy eye’. Amblyopia occurs when the brain is unable to process what one eye sees as well as the other, hence unable to see as clearly in one eye.

Amblyopia usually presents at birth or a young age, and if undetected can cause a permanent reduction in vision in the affected eye. Early detection can help preserve and improve vision, so that both eyes are able to see clearly.

Different types and causes of Amblyopia

There are three main types of amblyopia.

Covering one eye

1. Strabismic amblyopia

This is when one eye is unable to see as well as the other, due to an eye turn or drift. In this case, one eye can be seen to turn outwards or inwards. As one eye turns away, the brain favours the eye that is fixated correctly (the good eye), and only processes and receives input from the ‘good’ eye.

2. Refractive amblyopia

This is when one eye is unable to see as clearly, due to a large difference in refractive error. Refractive error refers to an amount of myopia (short-sightedness), hyperopia (long-sightedness), or astigmatism, which causes the vision to be blurry. A significantly larger amount of refractive error in one eye, causes an imbalance and hence, the brain favours the eye that can see clearer.

3. Visual depravation amblyopia

This is when amblyopia occurs due to vision being obstructed due to a cataract or other impeding condition. Cataracts are when the naturally clear lens inside the eye appears cloudy or hazy. This obstructs vision and causes the eye to be unable to see clearly or receive proper visual input.

Amblyopia Symptoms

Amblyopia can be easily missed in a lot of cases, as the good eye compensates for the decreased in vision in the amblyopic eye. Therefore, with two eyes open it will be difficult to detect that one eye is not seeing clearly. Some symptoms of amblyopia include an eye turn or drifting of one eye, lack of 3D vision or depth perception, hazy or blurry vision in one eye when covering the other eye.

How to Diagnose Amblyopia

The diagnosis of amblyopia can be determined with your eye care professional. They will check the level of vision in both eyes, to see if one eye does not see as clearly. And if so, they will do further tests such has binocular eye coordination test, prescription checks, and eye health checks, to determine what type of amblyopia you have. Determining the type of amblyopia will determine the type of treatment required.

Treatments for Amblyopia

The following are some of the most common ways to treat amblyopia:

  • - Spectacles to correct any vision blur

  • - Periodical patching of the good eye throughout the day, to stimulate the eye and brain connections for the amblyopic eye

Treatment for amblyopia is generally very successful if started early and followed properly. Amblyopia is a treatable condition, and the earlier it is detected, the better the visual outcomes. Therefore, it is important to have your eyes tested at an early age to screen and/or treat amblyopia.