The word lazy eye is a misnomer as there is nothing like a lazy eye. The word lazy eye means that there is a developmental problem where the signals from the brain are not being transmitted to the eye and hence the word lazy eye came up.
During the phase of development when nerve fiber fails to get mature, then it leads to transmission defects which cause lazy eye. In medical terminology, the lazy eye is known as amblyopia where one eye is receiving adequate signals while the other eye is deprived of signals thus seems like a lazy eye.
Stimulation is necessary for the functioning of the eye. When in early childhood education is deprived of stimulation which occurs usually when a child undergoes an eye surgery like in case of congenital cataract. The defective eye is bandaged for a considerable amount of time for recovery to occur. By that time the nerve cells fails to mature and hence in the absence of any signal, the eye becomes lazy. This is the reason it is advised to avoid patching of the eye in childhood because this is the time when nerve cells get mature and if this phase is an absent high chance of eye getting lazy.
In the United State, this condition is seen in two per cent of children who have undergone eye surgery.
What Are The Causes Of A Lazy Eye?
- Mostly seen after eye surgeries when eyes are patched for a considerable amount of time and nerve cells lose their ability to transmit signal or fail to develop.(1)
- It can be congenital as well when development did not take place and hence child is born with a lazy eye. Congenital lazy eye is tested by a simple trick. While driving when a child is able to follow the path that means if he keeps pace with the things going behind while driving or when his eyesight follows a tree until it gets out of vision. This is a reliable method to differentiate whether a person is malingering or not.(2)
- Strabismus is a condition which is usually encountered in children and here eyes usually do not aim at a specific target. This results in the formation of a double image which leads to confusion. So as to avoid this brain adapt by inhibiting signal from one eye and in this way one eye becomes lazy. Treating strabismus is the only treatment to get relief of symptoms.
- Refractive amblyopia- in this condition one eye is normal while another eye has got defective refraction and hence patient complains of blurry vision. And so as to avoid inconvenience to patient brain tries to suppress the blur signals from the eye and eventually that eye becomes lazy.
- Anisometropic amblyopia- Here the difference in refractive power of considerably high which causes overlapping of two different images. The brain adapts by accepting one image and rejecting the other. Inhibitory signals are given to the other eye. The eye which is inhibited in due course of time will become lazy. The only treatment in such condition is to treat the underlying cause.
- As per a few reports, Vitamin A deficiency is even considered a cause of lazy eye but still, it has not been proved. This hypothesis is under trial. Therefore patient is even supplemented with vitamin A in case of lazy eye. The results are not satisfactory thou.
- Convergence disorders are considered a cause of lazy eye.
- Cataract, trauma to the eye and prolonged patching in early childhood are usually the main cause of childhood amblyopia. Patch free interval should be given after surgery so as to allow stimulation to eye and maturation of nerve fibers. This is essential in a period of early childhood where stimulation plays are a significant role in the development of eyesight.
In all these conditions the only treatment is to treat the underlying cause. Early treatment is necessary else permanent defect is witnessed. The only key to get rid of this condition is proper awareness and timely management of the underlying cause.