Lazy eye is the common name for the eye disease “amblyopia”. It is marked by lowered vision that cannot be corrected by eye glasses or contact lenses such as focus dailies. Lazy eye is not caused by any eye disease, surprisingly.
What is Amblyopia?
The brain of the person who is affected by lazy eye fails to comprehend the images seen by the amblyopic eye completely. This condition, on a general level, affects only one eye of the victim. However, it can, quite possibly, reduce the vision of both eyes. It is estimated that 3% of children under 6 have some form of lazy eye.
A lot of people confuse lazy eye with the disorder of being cross-eyed, called strabismus. They are not the same conditions. The confusion is partly due to the fact that strabismus can possibly cause amblyopia. Constant unilateral strabismus can cause lazy eye in either of the eyes, whereas alternating or intermittent strabismus is a hardly a cause of amblyopia.
Moreover, strabismus can be easily detected as it a large turn in the eye. On the other hand, lazy eye without strabismus, or only a minor deviation is hard to detect with simple observation. Only an eye specialist who has experience in examining children and babies can detect this form of amblyopia. That is why both birth and pre-school eye exams are necessary.
What Causes Amblyopia?
Our eyes and brain coordinate to provide us vision. Light enters the eye and is converted into signals that are transmitted to the brain though the optic nerve. Lazy eye, therefore, describe visual disorders in one eye because it cannot longer coordinate with the brain in an appropriate way. Although vision is not totally lost from the weak eye, yet the brain favors the other one more than the amblyopic eye.
Both eyes of a person should receive clear images during a critical period between their birth and 6 years of age. Anything that hinders this can result in lazy eye.
Some of the causes of lazy eye are:
• Strabismus (crossed or turned eyes)
• Different vision in each eye
• Blockage in one eye due to lid droop
• Trauma to the eye
If only one eye sees clearly and the other’s vision is blurring, the brain will favor the strong eye by ignoring the eye with the faulty image. This can cause a permanent neurological condition which will force the person over time to think that the weak eye can never be improved with glasses, lenses like focus dailies or even Lasik surgery.
Finally, in rare cases, lazy eye can be caused by other eye conditions such as farsightedness, nearsightedness or astigma in one eye, or if the person has a cataract.
Diagnoses of Lazy Eye
Since this disorder only occurs in one eye, most children, and even parents cannot detect it easily. Most parents fail to have the eyes of their children checked at an early age, leaving such problems undetected till a later examination. Important tools for diagnosing lazy eye are the visual acuity tests along with the standard 20/20 letter charts. An additional examination with cycloplegic drops might also be needed to accurately diagnose the condition.
Treatment of Amblyopia
If detected at an early stage, treatment is usually easy. It involves:
• Visionary Therapy
• Eye Patching
Usually it is considered that examination and correction of vision before the age of 2 is the best treatment for lazy eye. However, new research disproves this. Studies show that procedures conducted even after the age of 7 can prove to be successful. There is no available report on the effectiveness of treating teenagers above 17, though adults have been treated for a long time successfully.
Lazy eye treatment also requires the person to make use of his/her weak eye. This is done in 2 ways.
This is a drug that is dropped in the strong once each day so that the vision will be blurred, encouraging the person to use the amblyopic eye. This helps to stimulate the brain to make increased use of the weak eye.
Finally, as the name suggests, the patient’s strong eye is patched with an opaque cover to achieve the same purpose as with the use of atropine.