Laser vision correction (LASIK and PRK)

Laser vision correction aims to reduce dependence on glasses or contacts. The cornea is the clear window at the front of the eye and does much of the work of focusing light. In nearsightedness, farsightedness and astigmatism, light does not focus exactly on the retina, so the image is blurry. During surgery, a precise laser removes a very thin layer of tissue and changes the curve of the cornea so light focuses better. The two long established methods are LASIK and PRK, and other techniques also exist. The procedure is short, done with numbing drops, and both eyes are usually treated on the same day.

In LASIK, a thin flap is first created in the top layer of the cornea using a laser or a fine instrument. The flap is lifted, the laser reshapes the tissue underneath, and the flap is laid back in place, where it stays without stitches. Because the corneal surface is largely left intact, recovery is fast. Many people see well the day after surgery, and discomfort usually lasts only a few hours. The flap requires a cornea of adequate thickness, and in rare cases it can shift after a direct blow to the eye.

PRK uses no flap. The thin layer of cells covering the cornea is removed and the laser reshapes the surface directly. A soft contact lens is placed as a bandage until the surface layer grows back. Recovery is therefore slower: the first few days usually bring pain, burning, tearing, light sensitivity and blurry vision. Vision improves gradually over days to weeks, and it can take a few months to reach full sharpness. The advantage is that more corneal tissue is preserved and there is no flap that could shift.

Final results with both methods are usually similar; the main difference is the path there. LASIK offers a faster and more comfortable recovery. PRK is often preferred for people with relatively thin corneas, for those in contact sports, martial arts or jobs with a risk of eye injury, and sometimes for people with dry eye. The choice is made with your eye doctor based on corneal thickness and shape, the size of your prescription, lifestyle and personal preference. Sometimes the answer is that neither method is suitable, and other options can be discussed.

A thorough exam comes first. Good candidates are usually adults whose prescription has been stable for at least about a year, with a healthy cornea of adequate thickness and no active eye disease. Testing includes corneal mapping, thickness measurement and a dry eye check. Surgery is usually not suitable with keratoconus or signs of a weak cornea, a cornea that is too thin, severe uncontrolled dry eye, a prescription that is still changing, pregnancy or breastfeeding, or uncontrolled systemic disease. Contact lens wearers usually pause them before testing.

After surgery you will use antibiotic and anti inflammatory drops plus lubricating drops. In the first days, avoid rubbing your eyes, eye makeup, swimming pools and dirty water, and keep your follow up visits. Dry eye is very common afterward and usually improves gradually over weeks to months. Halos and night glare are also common at first and usually fade. Sometimes a small prescription remains, and a touch up or glasses for certain tasks may be considered. Keep in mind that surgery does not prevent the need for reading glasses, which usually appears somewhere in your forties or fifties, and it does not guarantee life without glasses in every situation.

Serious complications are rare. Contact your eye surgeon right away for pain that gets worse instead of better, vision that drops after it had improved, marked redness, discharge from the eye, or any blow to the eye during recovery. A sudden drop in vision or a shadow or curtain over your vision also needs urgent assessment. Some pain in the first days after PRK is expected, but pain that increases after a few days or comes with discharge needs to be checked.