Amblyopia : Lazy Eye

Amblyopia is a decreased vision in an eye or both. In essence, it is the underdevelopment of the visual function of the eye. The term amblyopia is from a Greek word that literally means “lazy eye”.


It occurs when the causes that produce it work during the visual system development period, in the first 7-8 years of life. Therefore, only children develop amblyopia. It is caused by any factors that reduce the visual input of the eye.

Causes of Amblyopia (Lazy Eye)

The main causes are:

Anisometropia: a defect of unequal focus between the two eyes (anisometropic amblyopia). In this case, the parents and pediatrician may not suspect the disease right away because the eyes remain perfectly straight and the unaffected eye sees perfectly. Therefore, typically, children with this type of amblyopia do not take ophthalmic examinations and the diagnosis is delayed until the first visual screening. It is usually done within the first 3 years of age.

Strabismus: any ocular deviation that does not allow binocular vision may be due to amblyopia (strabismic amblyopia). Obviously, the eyeball will be affected by this type of amblyopia.

Sensory Deprivation: any obstruction to the image formation on the retina (congenital cataracts, corneal leukemia, vitreous opacity, severe ptosis, etc.) may cause amblyopia on that eye. Without early treatment, the affected child will have a very low vision on that eye from then on.

A difference of 2/10 between one eye and the other that is justified by other causes is enough and necessary to diagnose amblyopia. This is relatively simple in children aged 3 years. Since amblyopia is readily curable on early diagnosis, the diagnosis can be based on indirect elements during the visit of the child under 3 years of age (lack of eye fixation, the negative reaction of the child to the closure of an eye, objective refraction in cycloplegia).

Therapy For Amblyopia

Early treatment is always the best. If necessary, it is also possible to correct children’s eyeglasses or lenses every few weeks to correct the refractive errors. Once the cause of the amblyopia has been identified, the visual function of the amblyopic eye must be rehabilitated. There are several rehabilitation treatments that can be associated.

The principal and most effective remains to be the patching of the good eye (non-amblyopic). The pediatric ophthalmologist may recommend the best patching regime for every specific case. The goal of the therapy is to ensure the best possible vision is each eye. Usually, patching is done before 8 years of age. Some cases of amblyopia can be resistant to therapy.

Amblyopia, that is classically defined as lazy eye, is a disease that can be recognized early in a very young child. Because of this, it is advised to visit the hospital early on after birth, at the age of 3 and 6 later. Amblyopia is a pathology that arises in the very first years of life due to the non-use of the affected eye.

This may be due to a refractive defect such as astigmatism, hypermetropia, and myopia that disturbs the vision of the eye. Therefore, at that point, the eye works incompletely and consequently, its vision cannot develop fully. In the presence of strabismus, it is easy to imagine that a deviated eye, crooked, will fail to develop. Other cases are having pathologies such as ptosis and cataract that are elements that totally interrupt the vision of the eye and completely eliminates its functionality, thus blocks its development.

The first important thing is to resolve the cause. With a simple use of corrective eyewear to address the presence of astigmatism, hypermetropia or myopia, it will be possible to have a focused image in order for the eye to be in the best condition, able to see, work well, and develop vision.

In the case of strabismus with a marked elevation angle, it should corrected surgically, put it on the axis to allow it to be used completely. The next step is to use the patching therapy.

Patching the healthy eye allows the amblyopic eye to work and recover its visual functionality. Occlusion therapy should be carefully followed by a specialist ophthalmologist. In terms of time and duration, using that patch daily within 6 years of life will allow recovery of the affected eye. It will be difficult to achieve better results after 6 years, so it is unnecessary to carry out the therapy.