Lazy eye, known also by the medical term amblyopia, is a condition in which one eye loses vision due to serious refractive error, occlusion of the eye, or problems with the eye muscles (strabismus). As a result, good visual signals are not sent to the brain. In turn, the brain focuses on the signals from the dominant eye, so the nondominant eye atrophies.
Amblyopia is diagnosed most often in children, and treatment can begin from infancy to age 7. By the time the child is 8 years old, vision is less likely to respond to treatments, surgical or nonsurgical. If your child has serious amblyopia, your optometrist may recommend surgery; otherwise, they will focus on noninvasive treatments like eye patches or eye drops. Some individuals considering laser surgery wonder whether the laser eye surgery can fix an additional eye problem, such as a lazy eye.
What Is Lazy Eye?
The colloquial term “lazy eye” refers to a condition known among optometrists and ophthalmologists as amblyopia. This condition typically begins just after birth and develops up to 7 years old.
Although lazy eye can result in partial blindness, which impacts the overall quality of life, diagnosing it early is fairly simple. There are several treatments that can improve eye strength and prevent blindness. Symptoms of lazy eye include:
- One eye that wanders inward or outward.
- Eyes that do not seem to work together to focus on objects.
- Trouble with depth perception.
- Squinting or shutting one eye to see better or force the eyes to work together.
- Tilting the head.
- Abnormal results on vision screen tests.
The underlying issue leading to lazy eye is not a problem with the structures of the eye itself, but the connection to the brain. If a child has one eye that does not see as well as the other, the brain will focus on interpreting signals from the dominant eye, and the non-dominant eye will slowly lose its ability to see.
While many instances of lazy eye are obvious due to strabismus, there are several cases in young children in which the condition is not immediately obvious. To reduce the risk of amblyopia becoming more serious, a complete eye exam is recommended for children starting between the ages of 3 and 5.
Why Does Lazy Eye Develop?
- Strabismus (muscle imbalance): This is an imbalance in muscle strength between the eyes, so one eye is able to move more freely than the other. This leads the eyes to cross together or turn out away from each other, and it prevents them from tracking in a coordinated way.
- Refractive anisometropia (difference in vision sharpness between the eyes): Significantly different refractive errors in each eye (often due to farsightedness but sometimes caused by nearsightedness or astigmatism) can lead to one eye becoming stronger than the other.
- Deprivation: An early cataract, cloudiness on the cornea, or other visual problem in one eye can lead the other eye to quickly become stronger. Deprivation amblyopia in an infant is considered a serious risk and requires immediate treatment to prevent blindness.
Is laser eye laziness possible?
As with most LASIK questions, the answer to whether LASIK will fix a lazy eye can be answered only by your eye doctor or LASIK surgeon. This is because no patient’s vision is the same and the right vision correction solution for you will depend on your eyes’ unique shapes and degrees of refractive errors. In some situations, while not common, LASIK can be used to correct vision issues that will then subsequently reduce the degree of a patient’s lazy eye.
Typically, LASIK cannot help correct a lazy eye. But there might be an exception…
If one eye has significantly more nearsightedness, farsightedness or astigmatism than the other eye, it’s possible the brain will begin to ignore the eye with greater refractive error, leading to amblyopia.
Because the power of eyeglass lenses affects the size of images that reach the back of the eye, it can be very uncomfortable for people in this situation to wear glasses — the unequal magnification caused by the dissimilar eyeglass lens powers can make them nauseated.
Because contact lenses sit directly on the surface of the eye, dissimilar contact lens powers in the two eyes don’t cause the magnification problems associated with unequal eyeglass lens powers. So contacts usually are a better option than eyeglasses for people with dissimilar refractive errors that could cause lazy eye.
If a person with this condition (called anisometropia) cannot wear contact lenses safely or successfully, LASIK surgery might be the best way to fully correct their dissimilar refractive errors to prevent lazy eye.
If you’ve been told you are at risk of amblyopia if you don’t wear your glasses or contact lenses full-time, ask your eye doctor if LASIK might be a good option for you.
It’s important to understand the risks of LASIK if you already have amblyopia, however. Many doctors will not perform refractive surgery on the “strong” eye if the best-corrected vision in the amblyopic eye is 20/40 or less. Your eye doctor can discuss this further during your preoperative exam and consultation.
Reasons why laser eye surgery may be considered
The reasons why a person may consider laser corneal sculpting include:
- They can’t wear contact lenses and would prefer not to wear glasses for cosmetic reasons.
- They want to engage in work or leisure activities that cannot be done while wearing glasses or contact lenses.
- They don’t want the inconvenience of contact lens wear and the care required.
Medical issues to consider
People thinking about laser eye surgery should consider that:
- You should be at least 20 years old before you consider laser eye surgery.
- The refractive error (prescription in glasses) should be stable.
- People with diabetes, uncontrolled rheumatic conditions, diseases of the immune system or a family history of keratoconus should be very careful in proceeding with laser eye surgery. An experienced refractive surgeon will be able to advise you appropriately.
- Laser eye surgery carries extra risks if performed on people with abnormally shaped or very thin corneas. These are easily assessed during preoperative testing in a refractive surgeon’s office.
Laser eye surgery procedure
The excimer laser is a ‘cool’ type of laser. It doesn’t burn tissue, but vaporises small amounts of the cornea every time a beam of the laser is pulsed onto the surface of the eye. The diameter of the laser beam and the number of pulses that are directed onto the cornea are carefully controlled using computer technology, so that the surface of the cornea is reshaped.
The procedure is performed using local anaesthetic eye drops and takes between five and 10 minutes per eye. However, the time taken for the reshaping of the cornea with the excimer laser is usually less than a minute.
Different sight problems require different treatments. For example:
- Myopia – the central apex or peak of the cornea must be flattened to reduce the degree of short-sightedness.
- Long-sightedness – the central apex of the cornea needs to be made steeper. This is done by applying the excimer laser to the edges of the cornea.
- Astigmatism – this occurs when the cornea is more curved in one direction than the other so the laser is applied in a more linear fashion to make the cornea more evenly curved.
If the procedure is successful, the cornea is able to focus light rays directly onto the retina at the back of the eye, rather than in front of or behind the retina.
Immediately after the laser eye operation
After the operation, you can expect:
- Minor discomfort
- To be able to see, though not perfectly clearly
- That you will need to be driven home, or catch a taxi.
Side effects and complications of laser eye surgery
Possible side effects and complications of laser eye surgery include:
- Over or under-correction – this may be due to over treatment or under treatment. You may need a second ‘enhancement’ procedure for optimal results.
- Dry eyes – you may need to use lubricating eye drops.
- Infection – this is extremely rare, but treatment with antibiotics may be necessary.
- Sensitive eyes – some people report increased sensitivity to glare, which can make driving dangerous.
- Blurred vision – ‘halos’ or rings of fuzzy light may result from the treatment. Interestingly, this is no longer thought to be associated with large pupils as it was in the early days of laser vision correction.
Taking care of yourself at home
Be guided by your ophthalmologist, but general suggestions include:
- Use antibiotic and anti-inflammatory medication (in the form of drops) in the operated eye(s) for a period after surgery.
- Use plastic shields over the operated eye(s) for several nights after surgery to prevent damage caused by rubbing.
- Do not use pressure to rub the operated eye(s).
Other ways to treat lazy eye
Any or all of these issues in combination can lead to amblyopia. Fortunately, there are treatments that improve eye coordination and strengthen the muscles of the eyes. Treatments are more effective the earlier the condition is diagnosed. After a child reaches 8 years old, on average, the likelihood of vision improvement with treatment drops significantly.
There are several nonsurgical approaches to treating lazy eye. If amblyopia is due to an underlying refractive error, then the child will receive a prescription for glasses, so the affected eye can get used to seeing the world more clearly, which can improve its overall function. If the cause of amblyopia is strabismus, additional treatments may include:
Eye patches or eye occlusion
A patch is placed over the “good” eye, forcing the muscles in the lazy eye to develop greater strength. Since the brain still receives information from that eye, especially in younger children, it will not ignore the signals and will begin to interpret them. Treatment length will vary depending on how serious the eye’s turn was, how long it had been that way, and how old the child is. Eye patches should be comfortable and remain in place with a child’s regular level of physical activity. The child should not be able to see around the edges, including seeing light filtered through. There are decorated patches available for children to encourage them to wear the patch and to help them have fun during treatment. It is important to encourage your child to leave the patch in place.If your child already has eye glasses, there are patches that attach to the lens of one side of the glass, but this may be a second stage in the treatment process after the non-dominant eye has regained some strength. They are not good for children who are new to treatment.
Atropine eye drops
These may be applied to blur vision in the “good” eye. Like the eye patch, this forces the non-dominant eye to become stronger, and signals between that eye and the brain will become stronger. Drops are usually less conspicuous or awkward for the child.
Games and exercises designed to improve vision can strengthen the muscles of the affected eye. Games and activities include coloring in special workbooks, dot-to-dot drawing, word games, or using building blocks, depending on how old the child is. Home-based exercises may be recommended after the weaker eye has regained some strength. These may be done in combination with other treatments.
Although an optometrist or ophthalmologist will try less invasive treatments first, amblyopia may require surgery to treat strabismus, which is a problem with the muscles that move the eyes. This surgery can be performed in both adults and children. This reduces the eye turn, so the eyes line up better, by either loosening or tightening the muscles as needed. There are two types of strabismus surgery:
- Recession, when the eye muscle is detached and reattached further from the front of the eye to weaken the muscle
- Resection, when a portion of the muscle is removed to make the remaining muscle stronger
Like other eye surgeries, it is a one-day procedure that is outpatient, so your child does not have to stay in the hospital and can return to school after a few days. This procedure may improve vision, but it is not guaranteed to do so. In some instances, surgery is more cosmetic. However, surgery in concert with nonsurgical treatments like eye patches may reduce the risk of long-term vision loss.
Surgical treatments may also remove corneal ulcers and cataracts, adjust drooping eyelids, or correct other tissue damage from an injury or accident that hurt the eye.