What Is the Difference Between PRK and LASIK?
PRK and LASIK are two laser vision correction procedures designed to reduce dependence on glasses and contact lenses. Both reshape the cornea to correct nearsightedness, farsightedness, and astigmatism. The main difference lies in how the surgeon accesses the corneal tissue and how the eye heals afterward.
How PRK Works
PRK stands for photorefractive keratectomy. In PRK, the surgeon removes the thin surface layer of the cornea called the epithelium. After removing this layer, an excimer laser reshapes the underlying corneal tissue to correct the refractive error. At the end of the procedure, a soft bandage contact lens is placed to protect the eye while the epithelium naturally regenerates. The surface layer typically heals over several days, and vision gradually improves as the cornea recovers and smooths.
How LASIK Works
LASIK stands for laser-assisted in situ keratomileusis. In LASIK, the surgeon creates a thin corneal flap with a femtosecond laser. The flap is lifted to expose the inner corneal tissue. The excimer laser then reshapes the cornea and the flap is repositioned without stitches. Because the surface cells remain largely intact, initial comfort and vision recovery are typically faster than with PRK.
Access to the Cornea
PRK accesses the cornea by removing the surface layer. LASIK accesses the cornea by creating and lifting a flap. This single distinction drives most of the differences in comfort, recovery time, and risk profile between the two procedures.
Recovery Timeline
Recovery after PRK is slower. The surface cells need time to regrow and smooth out, which can take three to five days for initial healing and several weeks for vision to stabilize. Patients often notice fluctuations in clarity during the first month. Sensitivity to light and discomfort are common in the early days and are managed with medications and the bandage contact lens.
Recovery after LASIK is faster. Many patients see well by the next day and can resume routine activities within a few days. Vision tends to stabilize sooner because the surface cells remain intact and the flap protects the treated area.
Comfort After Surgery
PRK generally involves more early discomfort. Patients may feel burning, tearing, and a foreign body sensation while the surface heals. Pain is usually strongest during the first two to three days and improves as the epithelium regenerates.
LASIK is usually more comfortable in the early period. Some dryness, mild irritation, or light sensitivity can occur but tend to be less intense and shorter in duration than after PRK.
Safety Considerations
PRK avoids creating a corneal flap, which eliminates flap-related risks. This can be advantageous for patients who engage in contact sports, military or first responder duties, or occupations with risk of eye impact. Without a flap, there is no chance of flap displacement after trauma. PRK also preserves slightly more corneal tissue, which can be important for thinner corneas or higher prescriptions when tissue conservation matters.
LASIK has an excellent safety record but includes rare flap-related issues such as microfolds, buttonholes, or displacement from significant trauma. These events are uncommon with modern femtosecond lasers and careful technique. LASIK can also induce temporary dry eye symptoms due to corneal nerve disruption from the flap, although most patients improve over time.
Visual Outcomes
Both PRK and LASIK deliver similar long-term visual outcomes for appropriately selected patients. Studies show excellent uncorrected vision with high satisfaction in both groups. The main difference is the pace of recovery, not the final clarity. LASIK tends to achieve stable vision faster, while PRK takes longer to reach the same level.
Candidacy Differences
PRK is often preferred for patients with thinner corneas, irregular surface features, mild epithelial disease, or those at higher risk of eye trauma. It is also considered when corneal measurements suggest that preserving tissue is a priority. Patients with a history of recurrent corneal erosions or certain dry eye patterns may also be better suited to PRK.
LASIK is often chosen by patients who want rapid visual recovery and have adequate corneal thickness and stable prescriptions. It is a strong option for many people with routine refractive errors and healthy ocular surfaces.
Risk of Haze and Dryness
With PRK, there is a small risk of corneal haze during healing, especially in higher prescriptions. Surgeons often use medications during surgery and prescribe drops afterward to reduce this risk. Most haze is mild and temporary.
With LASIK, dry eye symptoms can be more noticeable in the early postoperative period due to the flap affecting corneal nerves. Symptoms typically improve over weeks to months with artificial tears and other supportive treatments. Long-term dryness is uncommon but can occur.
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