Lazy Eye(Amblyopia)

Amblyopia causes more visual loss in the under 40 group than all the injuries and diseases combined in this age group. If not detected and treated early in life, amblyopia can cause loss of vision and depth perception. Improvements are possible at any age with proper treatment, but early detection and treatment offer the best outcome. Comprehensive vision screenings are needed for infants and pre-school children. An eye exam by a pediatrician or the 20/20 eye chart screening is not adequate for the detection of amblyopia (and other visual conditions).

Amblyopia, commonly known as lazy eye, is the eye condition noted by reduced vision not correctable by glasses or contact lenses and is not due to any eye disease. The brain, for some reason, does not fully acknowledge the images seen by the amblyopic eye. This almost always affects only one eye but may manifest with reduction of vision in both eyes. It is estimated that 3% of children under six have some form of amblyopia.

Causes of Lazy Eye

Anything that interferes with clear vision in either eye during the critical period(birth to 6 years of age) can cause amblyopia. The most common causes of amblyopia are constant strabismus(constant turn of one eye), anisometropia(different vision/prescriptions in each eye), and/or blockage of an eye due to cataract, trauma, lid droop, etc.

Amblyopia is a neurologically active process. In other words, the loss of vision takes place in the brain. If one eye sees clearly and the other sees a blur, the brain can inhibit(block, ignore, suppress) the eye with the blur. The brain can also suppress one eye to avoid double vision. The inhibition process(suppression) can result in a permanent decrease in the vision in the blurry eye that can not be corrected with glasses, lenses, or lasik surgery.

Detection and diagnosis of Lazy Eye

An eye exam by a pediatrician or the 20/20 eye chart screening is not adequate for the detection of amblyopia(and other visual conditions). The most important diagnostic tools are the special visual acuity tests other than the 20/20 letter charts currently used by schools, pediatricians and eye doctors. Examination with cycloplegic drops can be necessary to detect this condition in the young.

Since amblyopia usually occurs in one eye only, many parents and children are unaware of the condition. Many children go undiagnosed until they have their eyes examined at the eye doctor’s office at a later age. Comprehensive vision evaluations are highly recommended for infants and pre-school children.

Treatment of Lazy Eye

• Early detection of factors causing amblyopia is most effective means of treating Amblyopia.
• Screening of child before he/she starts school by an ophthalmologist is absolutely a must.
• If the child has refractive errors in any of his/her eyes, then it has to be worn from a very early age.
• Special exercises with one eye patched for a specified period of time is the most & only effective treatment for improving a amblyopic childs eyesight.

Remember

If the squint is large it can be a cosmetic problem when the child grows up. However, another important complication is amblyopia. This means that vision can be gradually affected if the squinting eye is left untreated. As mentioned above, even in very minor squints, if the two eyes are not exactly straight they cannot focus on the same point. This confuses the brain as two images are seen at the same time causing double vision. The weaker image then tends to be ignored by the brain. This weaker eye then gradually loses its power(just like if you never use one arm it will become wasted and weak). This loss in vision takes years to develop but is irreversible. Therefore even very slight squints in children should be treated.

The aim of the treatment is to get the weaker squinting eye trained up. If the cause of the squint is due to one eye being more long-sighted then wearing glasses to correct this may do the trick. Sometimes wearing a patch on the good eye to train up the weaker eye is advised for part of each day. Eye muscle exercises are sometimes tried. If the squint is large and the above measures do not seem to be helping, then an operation is sometimes performed to correct the squint. Treatments are usually under the supervision of Orthoptists who are specially trained people who deal with all aspects of squint and work in close co-operation with eye surgeons.