The Difference Between Strabismus and Amblyopia
Strabismus and amblyopia are eye issues that can arise in people of any age. They are both functional vision issues, meaning that they affect how your visual system, such as your eyes, brain, and visual pathways, work together. Read on to learn more about how strabismus and amblyopia differ, their causes, and their treatments.
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What Is Strabismus?
Strabismus is also known as a wandering eye, and is caused internally by weak inner workings of the eye. However, it can be treated with a combination of a few methods. Take a look at the following information for a comprehensive overview of this eye condition.
Strabismus is an issue with the eye’s alignment. It causes the eyes to not look the same way or at the same place at the same time. One eye may turn inwards, outwards, up, or down either sometimes or all of the time. This is visible when someone has a crossed eye-- it typically is a symptom of strabismus.
You may be wondering how exactly strabismus is caused. It is a problem with one of the three visual skill areas that make up functional vision-- it is an issue with eye teaming. Eye teaming is the skill that allows both eyes to work together in a coordinated and precise way. Since, with strabismus, the eyes are pointing at different spots, this gives the brain trouble processing.
The brain has issues combining the two images from each eye into a single, three dimensional image.
The biggest and most obvious symptom is the observable eye turn of an eye upwards, downwards, inwards, or outwards. Those suffering from constant strabismus are typically less symptomatic than patients who have non-strabismic functional vision problems.
However, it is important to note that those with constant strabismus are still not asymptomatic.
The reason for this is that those with constant strabismus often suppress the information from the turning eye, which avoids some of the symptoms of poor eye teaming and double vision. Those who have intermittent strabismus usually experience more frequent symptoms of their functional vision problems. These symptoms could be headaches, poor depth perception, eye strain or eye pain, blurry or double vision, and eye fatigue.
Types of Strabismus
Strabismus has more than one variation. These different types of strabismus are based on factors such as which eye is turning, direction of the eye turn, amount of eye turn, frequency of eye turn, and whether or not the turn is the same in all positions of the gaze.
The most common of the strabismus types is esotropia, where one eye turns inward, towards the nose, rather than looking straight ahead.
Exotropia is an outwards turning of one or both of the eyes.
There is another type of strabismus, known as hypertropia.
Hypertropia occurs when either of a person’s eyes drift or look upwards.
There are a few different ways that strabismus can be treated. Surgery can be a way to treat strabismus, but it does not treat the cause -- the functional vision problem of poor eye teaming.
Surgery will only reduce the amount of eye turn that a person experiences. Several surgeries are often required to treat strabismus.
In order to treat the underlying root issue of this condition, vision therapy is typically required. During vision therapy, a person will learn to develop their eye teaming skills. Many cases require a combination treatment method of surgery and vision treatment, but it is always recommended that the option of vision therapy be attempted first, as it is of course less invasive than surgery.
Regular eye exams are a great way to stay on top of any eye concerns.
What Is Amblyopia?
You may be wondering what amblyopia is and how it is caused. Amblyopia is an eye condition often caused by strabismus, and typically does not have any outward visual symptoms, meaning that it can be tricky to pick up on at first. Read on for more information about this eye condition and how to treat it.
Amblyopia is an issue with eyesight itself. It is when a person is unable to see the image clearly in one or both of their eyes. This is often shown by a lazy eye. Unfortunately, even with prescription glasses, this vision issue still persists.
What causes amblyopia, anyway? Typically, strabismus does! Specifically, it is caused by the constant suppression of an image from one eye-- this eye will develop amblyopia. This is because when the image of one eye is affected, the brain will then suppress or turn off one of the images. If this is a case of amblyopia where both of the eyes are affected, though, the brain does not ever develop the ability to see clearly with both eyes.
Strabismus is easier to spot than amblyopia is. However, amblyopia does not have any outwards signs, so is trickier to determine and diagnose.
As this is an issue with a person’s functional vision, typical symptoms include eye strain or pain, poor depth perception, a head turn or head tilt, a squint or shutting of an eye, clumsiness, or issues throwing or catching things.
Fatigue with near work is also a symptom of amblyopia. Near work refers to activities that are done at a short working distance, such as reading, computer use, or writing.
Types of Amblyopia
There are actually three types of amblyopia with their differences being in the original cause of the suppression. All of the types of amblyopia result from the brain’s suppression of vision in either one or both of a person’s eyes.
Strabismic amblyopia results from a constant eye turn in one of the eyes, while refractive amblyopia results from an uncorrected high eye prescription in one of the eyes-- or in both! The third type of amblyopia is deprivation amblyopia. This is caused by impaired vision in one eye as the result of physical problems in that eye.
When it comes to treating amblyopia, a combination method is best. Typically, traditional treatment begins by prescribing a person a pair of glasses with corrective lenses, and then patching the person’s non-amblyopic eye with an eye patch. Prescription eye drops can also be used to “patch” or mask the non-amblyopic eye by blurring its vision.
Just like with strabismus, patching on its own will not solve the entire problem. It does not address the root cause of the eye condition. This cause is poor development of eye teaming skills. Vision therapy should also be prescribed with patching or eye drops so that a patient can develop their eye teaming skills and improve functional vision in order to prevent regression.
Frequently Asked Questions
Is amblyopia worse than strabismus?
Amblyopia is the medical term for a lazy eye, which is an issue with your eyesight or vision. Strabismus, however, is the medical term for “crossed eye” and is an issue with your eye alignment. One is not necessarily worse than the other, as they are slightly different issues with similar symptoms.
Can you have strabismus without amblyopia?
Amblyopia and strabismus often occur together, and strabismus is the most common cause of amblyopia. However, one can still occur without the other-- they are not exclusively linked.
What is the difference between a wandering eye and a lazy eye?
A lazy eye is an eye that is not working in sync with the brain, which causes poor vision in this particular eye. The brain relies on the stronger eye, which weakens the other eye, making it “lazy”. As the eye weakens, it also becomes a wandering eye, by wandering up and down, or sideways. This is also known as strabismus.
Does strabismus help amblyopia?
No, strabismus does not help to alleviate or cure amblyopia. In fact, it is a direct cause of amblyopia.
Can you have strabismus and amblyopia at the same time?
Strabismus is the most common cure of amblyopia, so amblyopia often occurs alongside strabismus. However, amblyopia can also occur without strabismus.
Does strabismus cause blindness?
Strabismus causes the eye to look in different directions, and is often a condition that appears in early childhood-- though it can also appear later in life. If left untreated, strabismus can have a detrimental, permanent effect on a person’s vision, which could possibly lead to blindness as well.
Can you go blind from amblyopia?
If amblyopia is not detected and treated early, the affected eye may never develop good vision and may even become functionally blind. However, with an early diagnosis and the right treatment, the sight in an amblyopic, or lazy, eye can be restored!
Can amblyopia get worse with age?
The effects of amblyopia begin in childhood, but symptoms can continue to worsen into adulthood if not detected or left untreated. In fact, children who develop amblyopia and are left untreated may even suffer from permanent vision loss before they reach adulthood. Seeking treatment for these issues is of the utmost importance.
Can strabismus worsen with age?
Yes, it can worsen with age as eye muscles begin to weaken and deteriorate. Additionally, strabismus can also occur in someone of more advanced age, though it typically appears during childhood.