What is LASIK Eye Surgery? Who is the LASIK Method Suitable For?

LASIK eye surgery (LASIK laser) is one of the most commonly used laser techniques to treat vision problems such as myopia, hyperopia, and astigmatism. It is a popular method due to its effectiveness and quick recovery time.

What is LASIK Eye Surgery?

LASIK eye surgery is a laser-assisted procedure used to treat common vision problems such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism—conditions that typically require the use of glasses or contact lenses. The term LASIK stands for Laser-Assisted in Situ Keratomileusis. This procedure involves the use of both a femtosecond laser and an excimer laser to reshape the cornea, improving the eye’s ability to focus light properly. LASIK is often preferred over other types of laser eye surgeries due to its painless nature and rapid recovery—many patients experience significantly clearer vision as soon as the next day.

In Which Eye Disorders Is LASIK Applied?

Myopia (Nearsightedness): LASIK can theoretically be performed for myopia up to -10 diopters. However, treatments above -8 diopters are uncommon and are considered only in select cases.

Astigmatism: LASIK is suitable for correcting astigmatism up to 6 diopters.

Hyperopia (Farsightedness): LASIK can be used to treat hyperopia up to +5 diopters.

Who Is LASIK Suitable For?

The values mentioned above represent the maximum treatable limits, but not every patient within these limits is automatically a candidate for LASIK. Suitability is determined by assessing how much corneal tissue will be removed to correct the existing prescription, based on corneal thickness measurements obtained through a corneal topography test. LASIK can only be performed if the remaining corneal thickness after the procedure is within safe limits.

For more detailed information on the types and techniques of laser eye surgery, you can refer to my article: “Laser Eye Surgery”

Who Is Not Suitable for LASIK?

LASIK surgery is not recommended for individuals with thin corneas, abnormal corneal steepening, or corneal diseases such as keratoconus. In patients with retinal tears, it is essential to first treat and stabilize the retina—usually with an argon laser—before considering LASIK.

Additionally, LASIK is generally not performed on individuals over the age of 40, except in special cases. This is because most people develop presbyopia (age-related near vision impairment) after 40. Even if distance vision is corrected through LASIK, reading glasses may still be necessary for close-up tasks.

For more information about the cornea, you can refer to my article “Understanding the Structure of the Eye and Its Functions?”

Preparation Process Before Surgery

Before undergoing LASIK surgery, a comprehensive eye examination is performed to determine the exact prescription that needs to be corrected. For patients who wear contact lenses, it is recommended to discontinue their use at least 4–5 days prior to the examination and surgery, as contact lenses can temporarily alter the shape of the cornea and affect test results.

How the Surgery Is Performed

Just before the LASIK procedure, anesthetic eye drops are applied to numb the eye. While these drops eliminate pain, a slight sensation of pressure or touch may still be felt during the surgery.

The procedure begins with the use of a femtosecond laser to create a thin flap in the upper layer of the cornea. In the past, this step was performed using a mechanical blade called a microkeratome, but this method is now largely obsolete in favor of laser technology, which offers greater precision and safety.

Once the flap is created, the surgeon gently lifts it to expose the underlying corneal tissue. An excimer laser is then used to reshape the cornea by removing microscopic amounts of tissue, effectively correcting the refractive error based on the patient’s prescription. After the laser application is complete, the flap is carefully repositioned, where it naturally adheres without the need for stitches. The entire procedure typically takes only a few minutes per eye.

Post-Operative Recovery Process

Approximately 45 minutes after the surgery, patients may experience stinging, tearing, and mild discomfort in the eyes. These symptoms typically subside within a few hours and are usually completely gone by the next day.

Most patients regain 90–100% of their optimal vision within 24 hours. In some cases, full visual clarity may continue to improve gradually over the next 1–2 days.

Things to Consider After Surgery

It is crucial for patients to begin using the prescribed eye drops immediately after surgery and to follow the dosage and application instructions carefully. Proper use of these medications helps prevent infection, reduce inflammation, and support healing.

In the first few days following the procedure, patients should avoid rubbing their eyes, applying excessive pressure, or sleeping on the operated eye. These actions can disrupt the corneal flap created during surgery and may lead to complications such as flap wrinkles.

Risks

The most significant risk associated with LASIK surgery involves complications related to the corneal flap. If post-operative care instructions are not followed properly, wrinkles or folds may develop in the flap, or an adverse reaction could occur beneath it. These issues can affect vision quality and may require additional treatment.

Conditions That May Occur After Surgery

Blurred Vision: Temporary blurred vision is common immediately after surgery and typically resolves within one day.

Light Flashes and Halos: Many patients experience light flashes or halos around lights, which usually subside within 2 to 3 weeks. In some cases, these symptoms may persist for a longer period.

Dry Eyes: A sensation of dryness is common, especially during the first six months following surgery, as the eyes gradually heal.

Near Vision Difficulty: Patients with high myopia may notice temporary difficulty focusing on close objects during the first month after LASIK. For those under 40, this near vision impairment is usually temporary.

Frequently Asked Questions (FAQ)