What is Lazy Eye?
Lazy eye refers to the drifting or misalignment of an eye. This is usually the manifestation of amblyopia, where one eye is experiencing significant vision loss, and sometimes also strabismus (or “crossed eyes”), a general misalignment problem.
Lazy eye occurs in 2-3 of every 100 children. In order to understand about lazy eye, we have to know how our eyes and brain work together to produce vision. Both of our eyes act like a camera which capture the image and this information will be sent to the brain and the brain will interpret the image that we are seeing. This is a learning process which begins soon when a child was born, similar to motor and language skills. The visual development continues, slowly a child learns to perceive colour, shapes, depth and motion. Any distruptions to the eyes and brain during this period may result in lazy eye.
Lazy eye / amblyopia: What’s the difference?
There are two main conditions that result in what we see as a lazy eye:
Amblyopia is a developmental problem with the eye-brain connection: the brain has basically learned to ignore information from one eye. Amblyopia is not a problem with the eye itself, though it can both cause and be caused by such problems.
Strabismus, or “crossed eyes”, is a misalignment of the eyes when the six muscles that surround and help focus the eyes are not working together properly. This can be both a cause and an effect of amblyopia.
How does a lazy eye affect my vision?
The most common symptoms of lazy eye are eye drifting and misalignment. But a lazy eye can cause serious vision problems:
Rapid loss of visual acuity in the lazy eye when left uncorrected and increasingly unused
Loss of binocular vision, leading to the inability to gauge depth.
Increased risk of vision loss for the stronger eye, since vision problems that typically occur in both eyes will affect the stronger eye first.
The earlier a lazy eye is checked out and treated, the better the chances of success. However, lazy eye treatment for adults is also effective, especially when motivation and commitment are strong. Studies show marked improvement in visual acuity of the weaker eye in older patients, though often with diminished rate, degree and extent of recovery.
There are two main steps to amblyopia treatment, the first part of lazy eye correction:
Step 1: Correcting vision problems
Eye conditions, such as cataracts, and refractive errors need to be corrected first and foremost. This is often as simple as prescribing glasses for near or farsightedness. Sometimes, in mild cases, correcting the vision of the weaker or lazy eye is enough for realignment.
Step 2: Retraining the eye-brain connection
In most cases, eye doctors block the stronger eye in order to train the brain to start recognizing the image from the amblyopic or lazy eye. This can be done with a patch or with eye drops that temporarily blur vision.
Eye muscle surgery
Occasionally, even the correction of amblyopia doesn’t correct strabismus issues that keep the eyes misaligned. In these cases, eye muscle surgery to strengthen or weaken certain muscles can help. A surgeon will either resect (or shorten) a muscle to strengthen it or recess a muscle (attaching it to a farther location) to weaken it.
In a small number of cases, mild misalignment due to convergence insufficiency (where the eyes have difficulty turning in to focus on close objects) can be corrected with eye muscle exercises. These eye exercises include pencil push-ups and computer vision therapy.
Remember, the earlier you treat a lazy eye, the higher the chances of success. Anytime you have problems with your eyes or vision, chat with your eye doctor as soon as possible.
Is there any way to prevent it?
There is no way an infant or young toddler can tell the parents about their poor vision, unless there is an apparent abnormality that are visible to parents. Due to this reason, lazy eye problem usually present late. One simple way to prevent this is to bring your child for vision test and eye examination at least once before they enter the school, ideally at the age of 4 when they are able to co-operate and give response during the vision test.