Amblyopia is a decrease in visual function in one or both eyes due to an abnormal ability of the visual pathway during childhood. Amblyopia does not necessarily imply an obvious problem in the eye. Vision loss occurs when neural pathways between the eye and the brain are not properly stimulated during recommended age. With the amblyopic eye, brain only “learns” to see blurry images, even when using glasses at a later age. As a result, brain starts “favoring” one eye at the expense of the other – this is generally known as “lazy eye”. It is the main cause for vision loss between children.
“Normal” vision is a learning process one acquires during the first years of life. In newborns, vision is very rudimental; however, vision improves when babies are stimulated because vision centers in the brain start developing. If the eyes of the baby are not capable to capture “sharp” images, then the vision centers cannot properly develop. Consequently, vision decreases, despite the normal appearance of the eye’s anatomical structure.
The most common causes are refractive errors in one or both eyes that were not corrected during early childhood, then resulting in a poor development of visual function in the affected eye(s) – refractive amblyopia. Another common cause is strabismus – squint amblyopia. More seldom, it is possible to develop a structural anomaly that damages visual function like ptosis (dropping eyelid) or opacity in the visual axis such as cataracts – privation amblyopia. Several etiological factors might coexist.
Amblyopia is treatable and reversible when causes are detected and eliminated at an early stage. The triggering element is always the treatment’s target. Besides the use of eyeglasses or surgeries, suitable case by case, a more or less long time frame might be needed for an eye penalty of the “good eye” – through occlusion or eye drops – so that the visual ability of both eyes can be balanced.
Screening is fundamental, even if your children seem to have a clear vision!