For people with blurry vision, the solution is to typically wear eyeglasses or contact lenses. However, for those with
refractive errors, eyeglasses and contact lenses may not be the most effective treatment to correct their vision. In these
cases, many opt to receive refractive surgery for vision correction. Refractive surgery is a general term for a group of
procedures to fix these vision impairments known as refractive errors.
A refractive error is a common vision problem that occurs when the shape and/or length of the eye is irregular and
prevents light from focusing correctly on the retina — these can include myopia (nearsightedness), hyperopia
(farsightedness), astigmatism (curvature of the eye), or presbyopia (loss of lens flexibility in the eye). In the United
States alone, there are about 150 million Americans living with refractive error.1
The most common sign of refractive error is blurred vision, but the type of refractive error must be diagnosed by an eye
exam. Treatment of refractive error can include eyeglasses, contact lenses, or refractive surgery.1
What is Refractive Surgery?
Refractive surgeries focus on repairing vision in one of two ways. The most common procedures will reshape the
patient’s cornea (the clear part of the eye) to allow light to properly focus on the retina (the back of the eye) while the
less common procedures involve replacing the natural lens of the eye.2
What are the Types of Refractive Surgery?
There are numerous types of refractive surgeries available for vision correction, so it is important to understand what
each type entails:
- LASIK, Laser in-situ Keratomileusis: A procedure for those who are nearsighted, farsighted, or have astigmatism. In aLASIK procedure, “the doctor makes a flap in the outer layer (epithelium) of the cornea to get to the tissue in themiddle of the cornea (stroma). A laser is then used to reshape the corneal tissue underneath the flap (stroma) so itcan focus light properly.”2
- PRK, Photorefractive Keratectomy: A procedure used to correct mild to moderate nearsightedness, farsightedness,
or astigmatism. Like LASIK, a surgeon uses a laser to reshape the middle layer (stroma) of the cornea. This surgery
is different from LASIK because there is no flap. Instead, the top layer (epithelium) of the cornea is removed to allow
the surgeon access to the middle layer (stroma) for the laser to reshape it. The patient will regrow the top layer
(epithelium) of the cornea during the first week of the post-operative period. - RLE, Refractive Lens Exchange: A procedure to correct farsightedness, nearsightedness, astigmatism, and
presbyopia. It can correct a broader range of refractive error types and magnitudes compared with LASIK and PRK.
It provides a surgical option for patients with a thin cornea or other minor corneal problems that would disqualify the
patient from LASIK or PRK. For this procedure, the doctor makes a small cut at the edge of the cornea, and the
natural lens is removed and replaced with a plastic lens implant.2 - PRELEX, Presbyopic Lens Exchange: A procedure similar to cataract surgery that is used for presbyopia, which is the
loss of flexibility in the eye that makes it difficult to see objects up close. The doctor removes the natural lens and
replaces it with a multifocal or Light Adjustable lens. These lenses allow for better vision of objects near and far.2 - Intacs, Intracorneal Ring Segments (ICR): A procedure used to fix keratoconus, an inferior steepening of the cornea that causes it to thin and results in a “cone” shape, causing blurry vision. For this procedure, the doctor makes a small incision in the cornea and places two crescent-shaped plastic rings in the middle layer (stroma) along the outer edge of the cornea. The rings help flatten the cornea, restoring a more rounded shape that allows light rays to focus on the retina in a more normal way.2
- ICL, Implantable Contact Lenses or Phakic Intraocular Lens Implants: A procedure originally created for those who
do not qualify for LASIK or PRK due to very high nearsightedness. However, recent FDA approval allows this
procedure to be completed for lower nearsighted powers, so it is used as an alternative option to LASIK/PRK. In this
procedure, the doctor makes a small incision at the edge of the cornea and inserts the ICL behind the iris but in front
of the natural lens.2 - LRI, Limbal Relaxing Incision: A procedure used to correct astigmatism. With astigmatism, the eye has more of an
oval shape like a football instead of being round like a basketball. The doctor makes one or two incisions at the
steepest part of the cornea outside of the visual axis. This helps the cornea to relax/flatten and changes the shape of
the eye to be more rounded. This is completed in conjunction with other procedures like LASIK, PRK, RLE, etc.2
Who Would be a Good Candidate for Refractive Surgery?
Someone that meets the following criteria may feel that refractive surgery is the best option for them:
- Has been diagnosed with a significant refractive error (farsightedness, presbyopia, nearsightedness, astigmatism)
- Looking to decrease their need for glasses or contacts
- Does not have any eye disease
- Is willing to accept the possible side effects of refractive surgery
- Understands that eyeglasses or contacts may still be needed post-surgery3
What are the Long-term Benefits?
Refractive surgeries are often successful in improving vision so that glasses and contact lenses are no longer needed daily. Most people who have had LASIK achieve 20/20 vision or better.4
In addition to improved quality of life, better vision can save money since it would negate the need for new glasses and contact lenses.
What are the Possible Risks of Refractive Surgeries?
Like with any surgery there are risks. Some of the risks associated with refractive surgeries include:
- Risk of infection may delay the healing process and can cause discomfort.
- Under-correction or over-correction can occur where glasses may still be needed post-surgery.
- Worsened vision is possible although it is rare.
- Excess corneal haze may occur as a natural part of the healing process after surgery. This is typically detectable by
eye exam so there may be no outward signs. This can result in a need for medication or an additional procedure. - Regression can also occur over time so a second procedure may need to be done.
- Halo effect can occur which makes the eyes see a second image, especially when driving or in dark environments.
- Damage may occur to the flap on the center of the cornea when LASIK is performed. This may have to be
repositioned.2
Conclusion
For many people with vision problems, refractive surgery offers the life-changing potential for better vision without the
need for glasses or contact lenses. Consulting with an eye care professional to better understand the difference in types
of procedures is an important step towards making the decision to obtain better vision.
Disclaimer: This article is for informational purposes and should not replace professional medical advice. Always consult with a qualified eye care professional before making any surgical decisions
Resources & References:
1: https://www.nei.nih.gov/learn-about-eye-health/eye-conditions-and-diseases/refractive-errors
2: https://www.webmd.com/eye-health/overview-refractive-laser-eye-surgery
3: https://www.aao.org/eye-health/treatments/what-is-refractive-surgery
4: https://www.mayoclinic.org/tests-procedures/lasik-eye-surgery/in-depth/lasik-surgery/art-20045751