Given that the refractive correction of anisometropia by means of spectacles typically leads to different image magnification for the two eyes, which may in turn prevent binocular vision, a refractive correction using contact lenses is to be considered. Also pediatric refractive surgery is a treatment option, in particular if conventional approaches have failed due to aniseikonia or lack of compliance or both.Frequently, amblyopia is associated with a combination of anisometropia and strabismus. In some cases, the vision between the eyes can differ to the point where one eye has twice average vision while the other eye is completely blind. Deprivation and occlusion
Deprivation amblyopia (amblyopia ex anopsia) results when the ocular media become opaque, such as is the case with congenital cataract or corneal haziness. These opacities prevent adequate visual input from reaching the eye, and disrupt development. If not treated in a timely fashion, amblyopia may persist even after the cause of the opacity is removed. Sometimes, drooping of the eyelid (ptosis) or some other problem causes the upper eyelid to physically occlude a childs vision, which may cause amblyopia quickly. Occlusion amblyopia may be a complication of a hemangioma that blocks some or all of the eye. Other possible causes of deprivation and occlusion amblyopia include obstruction in the vitreous and aphakia. Deprivation amblyopia accounts for less than 3% of all individuals affected by amblyopia.
Cause
Amblyopia has three main causes:

Strabismic: by strabismus (misaligned eyes)
Refractive: by anisometropia (difference of a certain degree of nearsightedness, farsightedness, or astigmatism), or by significant amount of equal refractive error in both eyes
Deprivational: by deprivation of vision early in life by vision-obstructing disorders such as congenital cataract

Strabismus
Strabismus, sometimes also incorrectly called lazy eye, is a condition in which the eyes are misaligned. Strabismus usually results in normal vision in the preferred sighting (or "fellow") eye (the eye that the person prefers to use), but may cause abnormal vision in the deviating or strabismic eye due to the difference between the images projecting to the brain from the two eyes. Adult-onset strabismus usually causes double vision (diplopia), since the two eyes are not fixed on the same object. Childrens brains are more neuroplastic, so can more easily adapt by suppressing images from one of the eyes, eliminating the double vision. This plastic response of the brain, interrupts the brains normal development, resulting in the amblyopia. Recent evidence points to a cause of infantile strabismus lying with the input to the visual cortex.Those with strabismic amblyopia tend to show ocular motion deficits when reading, even when they use the nonamblyopic eye.