Lazy Eye: (amblyopia)At birth the human visual system has not yet developed to its full and normal level , and this happens in the first 3 to 5 years of life. For normal vision to develop, clear and sharp images of the outside world should be formed on similar area of the retina of both eyes, especially on both maculas. Any obstacle in that process in one eye will make the visual center of the brain to functionally connect to the eye that sends clearer images to that center and consequently the other eye will not be used visually by the brain and therefore not to fully develop its vision , so the visual acuity of this eye will be at the level of vision at the earlier time of visual development.Causes of unclear image in the retina can be:

1- Any opacity in the way of transmission of light to the retina, like congenital or acquired corneal opacity in one eye, congenital or traumatic cataract in one eye , and if present in both eyes ,worse in one eye. That is why early treatment of any of these problems are important in preventing that eye to become visually LAZY.

2 – If one eye turns in or out ( crossed eye – strabismus) for long time in which case the brain will use the straight eye and therefore develop good vision in that eye and the crossed eye will become LAZY.

3 – If the child is more farsighted in one eye than the eye or has more degree of astigmatism in one eye , that eye will have less clear image on the retina in the involved eye and will become LAZY.

Among the causes of lazy eye the ones that are easier to be seen by mother or any family member -like crossed eyes or opacity of the cornea – will be seen by eye doctors earlier too.

The treatment for lazy eye is preventive if possible ,by eliminating the obstacle to the vision followed by patching of the good eye if needed to improve the reduced vision in the other eye .

In case of existence of different degree of farsightedness or astigmatism that can cause lazy eye in the worse eye the early refraction (test to find out necessity of corrective eyeglasses ) is very important in allowing sooner patching of the good eye and gradually improving the vision. Patching the eye with better vision is usually effective until age 6 to 8 , and beyond that age the development of the vision has completed by the brain and further improvement in vision is usually not possible. For this reason children should be screened for their vision by their doctor to detect any inequality in the vision of both eyes and referral to eye doctors for diagnosis of the lazy eye and starting the treatment as soon as possible.

For congenital cataract in one eye pediatric eye doctors prefer to do surgery in as soon as the first two months of birth, and even recently they recommend using lens implants in these babies too to avoid prescribing thick corrective eyeglasses or contact lenses after cataract surgery. According to the reports the result of implanting intra-occular lenses have been promising.