The good news is that both PRK (photorefractive keratectomy laser eye surgery designed to correct mild myopia and astigmatism) and Lasik procedures involve few risks. In fact, serious vision-threatening complications are minimal. However, as with any form of surgery, there can be potential side effects. Here are the most common side effects that can result from laser eye surgery:

Infection And Delayed Healing

Approximately one-tenth of one percent of all patients suffer from a corneal infection after undergoing PRK. Slightly fewer face an infection after Lasik. A cornea infection will not result in any long-term effects, however there generally is some additional discomfort and the healing process is slower.

Under Correction/Overcorrection

Even though tremendous advances have been made in laser eye surgery, a surgeon cannot predict precisely how your eyes will respond to the procedure. In some cases, you might need to continue to wear corrective lenses after surgery. If the results are particularly unsatisfactory, you do have the option to undergo a second surgical procedure to improve your vision.

Decrease In Best-Corrected Vision

After laser eye surgery, a few patients find that their best-corrected vision with contact lenses is actually worse than it was before the surgery. This is a rare occurrence, but can occur if there's been irregular tissue removal or if a corneal haze has developed.

Excessive Corneal Haze

Corneal haze is not unusual. In fact, it's part of the normal recovery process after refractive surgery. Generally, it won't affect your final vision, and will only be evident to an ophthalmologist using a microscope. However, in some cases, excessive corneal haze does interfere with your final vision. In such a case, it can often be corrected with a second surgery. Also worth noting, the risk of encountering excessive corneal haze is much lower with Lasik eye surgery than with PRK.

Regression

Regression is exactly as it sounds: for some patients, after a period of several they find their vision returning to its pre-surgery state. In other words, they find the surgery to be ineffective. A second surgical procedure is usually possible in such cases.

Halo Effect

The halo effect will generally go unnoticed except in situations where the light is dim. As the name implies, a second faded image is seen as the pupil enlarges. This image is produced by the untreated peripheral cornea. The danger here is that the halo effect can often interfere with your night driving.

Flap Damage or Loss

In some Lasik cases, instead of creating a hinged flap on the center of the cornea, the entire flap comes off. This can usually be replaced after the laser treatment. However, in some cases, the flap may be damaged or lost.

Distorted Flap

Also in reference to the Lasik procedure, if the healing of the corneal flap is irregular, then the shape of the cornea can become distorted. This will often result in your best-corrected vision being disappointing.

Other Side Effects of Laser Eye Surgery

Even when both the procedure and the healing process seem to go perfectly, there are some side effects that may still cause dissatisfaction. Older patients, for example, cannot have both distance and near vision in the same eye without wearing glasses or contact lenses. Patients suffering from myopia but who could still read without glasses may no longer be able to read without glasses after surgery. And finally, if both eyes are not treated at the same time, the eyes might work awkwardly together between the time of the first surgery and the second surgery.