By Carolyn Shih
Laser vision correction has revolutionized how millions of people see the world, offering a life-changing alternative to glasses and contact lenses. For many, it represents the freedom of waking up with clear sight. But what exactly is this procedure, and is it the right choice for you?
How laser vision correction works. Clear vision depends on the eye’s ability to correctly focus light onto the retina, a process called refraction. In cases of nearsightedness (myopia), farsightedness (hyperopia) or astigmatism, the light focuses incorrectly, resulting in blurred vision.
Laser vision correction, often referred to as laser eye surgery, uses a highly precise, computer-controlled laser to reshape the cornea — the clear, dome-shaped front surface of your eye. By subtly altering the cornea’s curvature, the procedure enables the eye to correctly bend light and focus it sharply on the retina, thus correcting the refractive error.
There are two main forms of laser vision correction:
LASIK (laser-assisted in situ keratomileusis). During LASIK, a surgeon creates a thin, hinged flap on the cornea’s surface using a laser, folds it back, uses a second laser to reshape the underlying tissue, and then gently repositions the flap. The entire process is quick, often taking less than 30 minutes for both eyes, and is known for its rapid visual recovery.
PRK (photorefractive keratectomy). Instead of creating a flap, the surgeon removes the cornea’s outermost layer (the epithelium), which naturally grows back. PRK is often preferred for those with thinner corneas or highly active lifestyles, as there is no flap-related risk, but the recovery time is longer and may involve more initial discomfort.
Benefits and rewards. The main allure of laser vision correction is the significant reduction or elimination of reliance on glasses and contact lenses. For suitable candidates, the benefits are numerous and can profoundly impact daily life:
Convenience: Enjoy activities like swimming, hiking or simply waking up without searching for your glasses. Some patients have issues like allergies, which are worsened by wearing contact lenses. This may be somewhat alleviated after having laser vision correction.
Cost savings: Over a lifetime, the one-time investment in surgery can be less than the accumulated cost of purchasing and maintaining corrective lenses.
Rapid results: With LASIK, many patients notice dramatically improved vision within 24 hours.
High success rate: Modern laser procedures have a very high success rate in achieving 20/20 vision or better, or at least excellent vision that significantly reduces the need for correction.
Who is a candidate? You must be at least 18 to undergo the procedure, and have stable vision, with a prescription that has not changed for at least a year. (Refractive surgery can treat myopia up to -12.00 D, astigmatism up to 6.00 D, and hyperopia up to 6.00 D.) Your cornea needs to be thick enough for the procedure. If it’s too thin, LASIK can increase the risk of corneal ectasia and long-term vision loss.
For women who are pregnant or nursing, hormonal changes can affect your eye shape and healing.
Considering the risks. Like any surgical procedure, laser vision correction carries potential risks, which should be thoroughly discussed with your surgeon. While complications leading to vision loss are rare, minor side effects are common, especially during the healing period:
Dry eyes: This is the most common side effect, and can last for several months, often managed with lubricating eye drops. In rare cases, it can be permanent.
Visual disturbances: Patients may experience glare, halos or starbursts around lights, particularly at night. These symptoms usually improve over time, but can be persistent for a small percentage of people.
Under- or over-correction: In some cases, the laser removes too much or too little tissue, meaning the patient may still need a minor prescription or a second “enhancement” procedure.
Flap complications: Specifically with LASIK, there’s a small risk of issues with the corneal flap, such as displacement, though modern technology has made this uncommon. Patients who have an active lifestyle sometimes opt for PRK to prevent these complications.
Ultimately, the decision to pursue laser vision correction is a personal one. It requires a detailed consultation with a qualified eye surgeon who can assess your overall eye health, prescription stability and lifestyle to determine the best path to clear vision.
Dr. Carolyn Shih is an assistant professor at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, and works at South Shore Eye Care, a member of the Northwell Health Eye Institute.
