Amblyopia or lazy eye is a disorder that impairs normal vision in the amblyopic eye as well as binocular visual function in those that are affected. Diminished visual acuity and contrast sensitivity define amblyopia monocularly whereas decreased depth perception is one of the main signs of decreased binocular function. It all reads rather straightforward on paper but how exactly children perceive or do not perceive those impairments?
In a nutshell they do not. Indeed, very often they do not acknowledge that anything is wrong with their eyes and vision. Very often children appear perfectly normal without any noticeable difficulties whatsoever that can be related to their amblyopia. It is usually only on routine checkups at school that it is found that there might be something wrong with one of their eyes.
Since amblyopia usually evolves gradually and the children’s brain is highly plastic the image from the amblyopic eye, slowly but surely decreasing in its quality, can be easily suppressed by the kids’ brain, so that they do not suffer symptoms such as double or blurry vision at all. Sometimes refractive errors such as anisometropia can go for years before amblyopia is diagnosed and the treatment than might not be as effective due to its very late initiation. That said, the fact that children often do not notice the impairments does not mean that they are not there. Any amblyopia, bothersome to the child or not, has to be properly addressed.
Thankfully, frequent routine medical examinations that include basic visual acuity testing easily uncover that one of the kids’ two eyes is inferior to the other and further examinations to address this issue are then indicated.