LASIK surgery can correct vision as poor as -8.00 diopters for nearsightedness and around +6.00 diopters for farsightedness, along with up to 6 diopters of astigmatism.
However, individual results and suitability vary significantly based on your eye health and corneal thickness.
If you’ve been considering LASIK to ditch your glasses or contacts, understanding the limits of the procedure will help you determine if it’s right for you. This comprehensive guide dives into the worst levels of vision LASIK can correct, the factors that determine your eligibility, and alternative options if your prescription is beyond the procedure’s capabilities.
Understanding How LASIK Works
Before we discuss its limitations, it’s important to understand how LASIK works. LASIK is a type of refractive surgery that reshapes the cornea—the transparent layer at the front of the eye. By reshaping the cornea, LASIK ensures that light entering the eye is properly focused on the retina, creating clearer vision.
There are three major refractive errors that LASIK can correct:
- Nearsightedness (Myopia): People with myopia have difficulty seeing distant objects clearly. This is often due to the cornea being too curved or the eyeball being too long, which causes light to focus in front of the retina.
- Farsightedness (Hyperopia): Hyperopia is the opposite of myopia. It occurs when the cornea is too flat, or the eyeball is too short, causing light to focus behind the retina and making nearby objects blurry.
- Astigmatism: Astigmatism occurs when the cornea has an irregular shape, much like a football rather than a basketball. This irregularity causes light to focus unevenly, leading to distorted vision at all distances.
These refractive errors are typically measured in “diopters” (D), a unit that indicates the severity of the issue.
The Worst Levels of Vision LASIK Can Correct
1. Nearsightedness (Myopia)
LASIK is most effective for individuals with mild to moderate levels of myopia. Generally, surgeons recommend LASIK for myopia up to -8.00 diopters. Some studies and clinics suggest LASIK can manage higher prescriptions—up to -10.00 or even -12.00 diopters—but the procedure’s effectiveness and safety decrease as the prescription increases.
For people with myopia beyond -8.00 diopters, the thickness of the cornea becomes a critical factor. LASIK reshapes the cornea by removing tissue, and if too much tissue needs to be removed, it could compromise the structural integrity of the eye.
2. Farsightedness (Hyperopia)
With hyperopia, LASIK is generally recommended for prescriptions up to +6.00 diopters. While it is possible to perform the procedure on individuals with higher levels of hyperopia, the results may not be as predictable, and the likelihood of regression (the return of vision issues) increases.
Hyperopia correction via LASIK is more challenging compared to myopia. This is because the procedure involves steepening the cornea, which requires more precision and is less stable over time than flattening the cornea for myopia.
3. Astigmatism
LASIK is highly effective for astigmatism up to 6.00 diopters. Modern advancements in LASIK technology, like wavefront-guided lasers, allow for precise correction of irregularities in the cornea, making it possible to address significant levels of astigmatism.
However, severe astigmatism beyond 6.00 diopters may be difficult to correct with LASIK alone, and additional treatments (such as enhancement surgeries or other refractive procedures) may be required.
Factors That Impact LASIK Eligibility
Even if your prescription falls within the correctable range, there are several factors that can impact whether LASIK is a viable option for you:
1. Corneal Thickness
The thickness of your cornea plays a critical role in determining whether LASIK is safe and effective. LASIK involves removing small amounts of corneal tissue, so individuals with thin corneas might not have enough tissue to spare for the reshaping process.
2. Overall Eye Health
Good eye health is essential for LASIK. Conditions such as dry eye syndrome, keratoconus (a progressive thinning of the cornea), or existing eye injuries may make LASIK unsuitable. Additionally, individuals with significant cataracts or glaucoma may not be candidates.
3. Age
LASIK is typically recommended for individuals over 18 years old, once their vision has stabilised. Younger patients may still experience changes in their prescription, reducing the long-term effectiveness of the procedure.
4. Lifestyle Factors
Certain lifestyle or occupational requirements may affect your eligibility for LASIK. For instance, individuals engaged in contact sports or professions where impact to the eye is common might be advised to avoid LASIK due to the slight risk of corneal damage.
Alternatives to LASIK for Severe Prescriptions
If your vision falls outside of LASIK’s correctable range, don’t worry—there are alternative vision correction options available:
1. Photorefractive Keratectomy (PRK)
PRK, an older form of laser eye surgery, can correct a range of refractive errors similar to LASIK. Unlike LASIK, PRK doesn’t involve creating a corneal flap, which makes it a suitable option for those with thinner corneas.
2. Implantable Collamer Lenses (ICL)
ICL involves placing a small, implantable lens between the natural lens and the iris of the eye. This procedure is an excellent option for individuals with severe myopia or hyperopia beyond LASIK’s limits.
3. Refractive Lens Exchange (RLE)
Refractive Lens Exchange (RLE) is a procedure comparable to cataract surgery, wherein the eye’s natural lens is replaced with an artificial intraocular lens. This option is best for individuals with high prescriptions and for those over 40 experiencing presbyopia (age-related farsightedness).
4. Custom Contact Lenses
If surgery isn’t a suitable option, custom-designed contact lenses (such as scleral lenses) can provide clear vision for individuals with high prescriptions or irregular corneas.
FAQs
1. Is LASIK permanent?
Yes, LASIK provides permanent reshaping of the cornea. However, natural ageing processes, changes in the lens, or new vision issues may arise over time and cause changes to your vision.
2. How do I know if I’m a candidate for LASIK?
The best way to determine eligibility for LASIK is by consulting with an experienced LASIK surgeon. They will conduct a comprehensive eye examination and assess factors like your prescription, corneal thickness, and overall eye health.
3. What happens if LASIK doesn’t fully correct my vision?
If LASIK doesn’t fully address your refractive error, enhancement procedures can be performed. Alternatively, glasses or contact lenses can correct any remaining vision issues.
Wrapping Up
LASIK is a revolutionary procedure that has transformed the lives of millions by offering clear vision and independence from glasses or contact lenses. However, it does have limits, and understanding these can help you make a well-informed decision.
If you’re considering LASIK but are unsure if your prescription qualifies, consult with a qualified eye surgeon to explore your options. For those whose vision falls outside LASIK’s range, innovative alternatives like PRK, ICL, or RLE can provide hope for a better vision.
No matter where your vision stands, modern advances in eye care mean there’s likely a solution that suits your unique needs. The path to clearer vision is within your reach!
