Depending on the trigger that caused it, we distinguish the following types of amblyopia
Depending on the trigger that caused it, we distinguish the following types of amblyopia:
Amblyopia due to strabismus
When an eye squints, the image produced is very different from the image of the other eye and the brain is unable to fuse it into a single (stereoscopic) image, resulting in diplopia. The direction and type of strabismus are irrelevant. If diplopia is caused and the child prefers one eye than the other, the brain will suppress involuntary the second image in order to eliminate it. But when the child shows no preference to one eye and focuses sometimes with one and sometimes with the other (lateral strabismus), and eventually uses both eyes equally, the development of vision is usually normal.
Amblyopia due to deprivation of visual stimuli
This form of amblyopia is more severe and is due to causes that prevent the light from reaching the child’s retina, such as congenital cataracts, corneal opacities, a large drop or tumors of the eyelids etc. The treatment should be done immediately. A congenital cataract, for example, must be removed from the first days of life. Any delay may result in significant visual impairment.
Amblyopia due to high anisometropia
By anisometropia we mean the difference in refractive abnormalities that both eyes have. If this difference is large, then one eye can produce such a blurred image that the brain cannot fuse with the other from the 'good' eye. Then, as in the case of strabismus, repulsion of the failing second image is caused which results in amblyopia. The problem with heterometropic amblyopia is that it can easily escape the parents’ attention, since there is no obvious point, such as the deviating of the eye in strabismus. In any case, it should be treated immediately by administrating the appropriate glasses.
due to high ametropia
refractive abnormalities (ametropia) affecting both eyes, may lead to
bilateral amblyopia if not treated in time with the use of glasses.