Amblyopia (Lazy eye)

Did you know that the technical term for a lazy eye is amblyopia? When one of our eyes cannot achieve a normal level of vision, even after having been prescribed glasses (or contact lenses), it is considered to be amblyopic (a lazy eye). In short, amblyopia is a disorder of the normal visual development of the eye(s). 

Amblyopia almost always only affects one of the eyes. This is because the brain will (for reasons discussed below) favor one eye over the other and ignore the vision from the weak (or lazy) eye. This causes arrested development of the lazy eye and the result is poor vision.

When Does A Lazy Eye Start?

Lazy eyes can only come about during the early developmental years of life. Typically, this will be between infancy to about age 10.

Sign and Symptoms

It is important to understand that children will not realize on their own whether or not they have a lazy eye. Only an optometrist can detect and diagnose a lazy eye. However, some signs that could indicate that your child has a lazy eye include: 

  • An eye that wanders inward or outward
  • Squinting, shutting or covering an eye
  • Poor depth perception
  • Head tilting
  • Abnormal results of vision screening tests

What Causes Lazy Eyes?  

There are several ways that a lazy eye can develop. 

  1. An eye turn. When one eye turns inwards or outwards from the other eye, the brain will begin to neglect the eye that is not positioned properly. As a result, that eye’s development will be delayed. 
  1. An unusual prescription. Occasionally, one eye will develop farsightedness or astigmatism, while the other eye maintains perfect vision. If this is undetected, the eye with the prescription will perpetually see blurry, which will thus impede its proper development. 
  1. An eye occlusion. Children may be born with a condition which prevents light from reaching the inside of the eye, for example, a congenital cataract. When light is unable to stimulate the sensory portion of the eye called the retina, normal eye development will be impeded. 
  1. Reverse amblyopia. One of the ways to treat amblyopia is to place a patch over the eye that sees well. This forces the brain to pay attention to the amblyopic eye, causing it to improve over time. However, if patching is attempted for too long, the patching can cause amblyopia in the ‘good’ eye. 

Treatment for a lazy eye

In the majority of cases, amblyopia can be successfully treated when detected early enough. That is why it is crucial for children to see an optometrist at an early age. The first routine eye exam should be around age 3, and every year thereafter. 

Treatment usually begins with eyeglasses or contact lenses. When that alone does not yield adequate results, an eye patch, medication eye drops, or vision therapy may be added to the mix. 

All children in Ontario are covered for their visits to the optometrist by OHIP. Book an eye exam for your kids and yourself today at PSN Optical. Eye exams for young children are fun and easy, as shown in the video Kids eye exam at PSN in North York, taken by a parent at their child’s first eye exam. 

Sara Loshab