Lazy eye is a very common topic of concern among parents. Parents are often left confused and may be feeling overwhelmed and anxious about their child’s vision.
Before I start explaining what a lazy eye is, I would like to start by clearing out some common misunderstandings.
Firstly, A lazy eye is not a blind eye!
Secondly, not every eye turn is a lazy eye, and not every lazy eye is turned.
Thirdly, If caught early and the child was compliant with treatment, the surgery option is very very low compared with eye turns.
Lastly, patching only fixes one part of the problem, which is visual acuity or the sharpness of the image. Modern techniques encourage using both eyes at the same time to develop depth perception and hand-eye coordination.
Now that we’ve got that sorted, the medical term for lazy eyes is AMBLYOPIA, whereas STRABISMUS is used to medically name eye turns!
What Is Amblyopia?
Amblyopia is the result of poor or disrupted early visual development, usually occurring before the age of nine.
With normal vision processing, the brain combines the 2 very similar images received from both eyes into a single 3-dimensional image.
However, When there is a difference in vision between the 2 eyes, the brain decides to shut off input coming from the eye with reduced vision due to image confusion, this is known as suppression. The 2 images are no longer similar! The weaker eye shows a blurrier image or one of a different size. How can they be combined?! The brain ignores that eye and depends on the good eye for all the visual processing. The unused, forgotten, weaker eye becomes amblyopic.
We know now, that the amblyopic eye isn’t blind. It simply sees differently! If we close the good eye for a second, the brain puts that lazy eye back into work to process the visual surroundings.
How Is It Treated?
With this simple theory, traditional treatment mostly depended on patching! The good eye is covered for a couple of hours a day for a couple of months. With persistent patching, the brain “re-sets”, allowing for improved vision of the lazy eye, as well as, fusion to form a single image. Of course, treatment duration, wearing of glasses and eye exercises are case specific.
More modern forms of treatment depend on the concept of binocularity or the two eyes working together at once. Rather than fixing the weaker lazy eye alone, treatment focuses on improving the vision and function of the lazy eye without excluding or blocking the good eye. These forms of therapy usually involve using a frosted eye patch, red-green tinted glasses whilst playing a series of games. Video games, either using a tablet, PC or virtual reality is also becoming more popular!!
With advances in therapy the child will not only improve visual acuity or the sharpness of the image but also improve his quality of life.
This is because the eye is connected to the brain via a very complex system. Traditional patching has been proven to improve visual acuity. But the child has to “reconnect” other things that got lost or reduced with amblyopia such as hand-eye coordination, eye tracking (including the ability to read swiftly), and depth perception. This is mostly achieved via binocular vision therapy.
How Can I Pick Up If My Child Has Amblyopia?
Usually, amblyopia occurs in very young children. Infants born prematurely or with low birth weight are at a greater risk for the development of the condition.
In many cases, amblyopia is promptly picked up by a quick vision assessment by either the Gp, child nurse, optometrist or a health professional. It is very important to get your child’s eyes checked yearly, starting from birth.
The child may not know if their eye has poorer vision as the good eye is working harder to compensate for the loss. However, you may notice the following:
- Increased squinting or
- Child’s eyes are getting tired very easily.
- Increased eye rubbing
- Wandering of the lazy eye or even head tilting.
- Increased clumsiness and poor depth perception, such as difficulty in hand-eye coordination tasks (pouring liquid into cups- picking up and placing objects swiftly, coloring in the picture correctly, going up/down the stairs).
- Tendency to bump into objects on the same side of the lazy eye.
Note: these symptoms are not exclusive to amblyopia. Although none, one or more may be present, they are more indicative of eye turns that occur commonly in conjunction with amblyopia. Amblyopia is best picked up and confirmed by a series of tests performed by a health professional.
Types of amblyopia
Whilst the mechanics behind amblyopia are the same in every eye case (ignored image by the brain), amblyopia is further broken down into types and these types are categorized according to their causes.
Sometimes amblyopia may be caused by a physical obstruction to vision such as fringes or pre-existing eye conditions, such as congenital cataracts, causing disturbances in the visual pathway and making that eye weaker and amblyopic.
Refractive errors or the need to wear glasses due to reduced vision, may cause amblyopia if the difference between the 2 eyes is major.
The presence of an eye turn may increase the chances of having that eye become amblyopic but it is also case specific. Eye turns come in many different forms and symptoms, requiring many different ways of management.
Regardless of the type of Amblyopia, it is important to get your child’s eyes checked regularly for prompt detection and treatment of eye conditions.
It is understood that the brain-vision pathway is fully developed by the age of 9, making treatment beyond that harder
Reading ability of children treated for amblyopia