Lazy Eye is a term used to define an eye that cannot see to its full potential. You may be aware normally an eye should see 20/20. That means that a person standing at 20 feet should see what a normal person sees at 20 feet. If a normal person can see at 40 feet what you see at 20 feet than your vision is 20/40. If after correction with glasses or contact lenses the vision does not improve to 20/20 than the eye is termed as Lazy. The medical nomenclature is Amblyopia.
Let us understand why an eye becomes lazy. The role of eye is transfer information from the surrounding universe to the brain. The eye condenses the light reflected from various objects on the macula. Electric signals generated are transferred to the brain by optic nerve. A specialized area of the brain called the occipital lobe converts these neuroelectrical signals into vision.
Any flaw in this process leads to an Amblyopic or Lazy Eye. There are three types of Lazy Eye.
The first kind is Neurological. This occurs when there is an obstruction in the neurological pathway or the brain. If the optic nerve is not developed, or the conduction pathways are malformed the light is not transmitted to the grey matter. Also the brain may be underdeveloped due to infections or genetic causes. This is the most challenging kind; currently this is not amenable to treatment.
The second kind is deprivation amblyopia. If the light is prevented from reaching the macula, it fails to stimulate the brain. There are various causes for this. Cornea may be opaque. There may be cataract in the lens. The jelly behind the lens may be fibrotic and hazy. The good news is that treatment can be provided. The earlier it is instituted the better the chance of fixing the lazy eye. Cataract procedure may have to be performed even before the baby is one year of age.
The third kind is refractive Amblyopia. The cause is nearsightedness, farsightedness or astigmatism. When the eye is very small or very large or has astigmatism significantly higher than the corresponding eye it is at risk of developing Amblyopia. Here the light reaches the macula and messages are delivered to the brain. But the messages are distorted. Since the brain keeps receiving information it has the best potential to recover. The way to do this is to fix the refractory error. The correct procedure would be influenced by the age and the refractive power. If the numbers are in the range of Lasik eye surgery this may be the simplest procedure. In such instances Lasik may even be performed on kids as young as six years. Sometimes an artificial lens may need to be implanted over the natural lens. If the person is above fifty years of age a presbyopic implant may be the best option.
In summary Refractive Amblyopia has the best chance of improving. This is possible in kids, young adults and even older individuals.