Amblyopia (aka lazy or wandering eye) occurs when there is a reduced or loss of vision in one or both eyes.
What causes Amblyopia?
Common causes are :
Congenital cataract
Congenital glaucoma
Uncorrected refractive error
Strabismus - cross eye, squint
A common cause of amblyopia in children is a result of an ocular condition called strabismus - one eye that turns in, out, up or down. In this case, their brain chooses to “turn off” that eye, which prevents the ability for binocular vision. This is a result of the brain’s natural ability for efficiency and will choose the easiest path of least resistance. In the case of strabismus, this child would be disoriented and have double vision (diplopia) as a result of the two eyes pointing in different directions. The brain will switch off the connection to the strabismus eye as a compensation to prevent the double vision. A consequence of turning off the eye is that the connections between this eye and the brain weaken. This decline is what causes the lazy eye (amblyopia).
It’s common for people to confuse strabismus with amblyopia as these terms are often thrown around interchangeably. Strabismus is a problem with eye alignment, in which both eyes do not move together, and amblyopia is a problem with reduced visual acuity or eyesight.
Amblyopia rarely occurs in people beyond the age of 11-14 years old who’s cognitive and eye development is set for the rest of their life. As opposed to children under this age where their brain plasticity is high, and at risk for the loss of neuronal wirings like vision to one or both eyes.
Symptoms of Amblyopia:
An eye that wanders in-, out-, up-, downward
Poor eye-hand coordination i.e clumsiness
Poor depth perception
Excessive eye rubbing
Cool fact: The amblyopic eye is not blind! The diagram below shows that the amblyopic eye does see an image but just not so clearly.
How is Amblyopia diagnosed?
Early diagnosis and treatment is critical in preventing permanent vision loss. The majority of cases of amblyopia are correctable and treated by visual aids using prescription glasses or contact lenses. In some cases, vision therapy is required to learn exercises that improve binocular vision, eye muscle strength and coordination. Rarely, do people with a lazy eye need surgery.
Our comprehensive exam can determine the presence of amblyopia. The earlier it is diagnosed, the greater the chance for a successful outcome. This is why our optometrist recommends a child’s eye health exam should be between 6-12 months and then should continue on annually.
Alberta Health Care contributes to children’s basic eye exams before the age of 19. At Respect Eyecare, we recommend retinal imaging for all kids 3 years and older to offer the best standard of practice in eyecare.
About the Author
Dr. Steven Hoang received his Doctor of Optometry at the University of Waterloo. He serves as the owner and full-time eye doctor of Inglewood and Ramsay at Respect Eyecare. His special interest is in contact lenses and dry eye syndrome.