How Lasik Works

Eye Reflecting Examination Chart

LASIK, which stands for “laser-assisted in situ keratomileusis,” is the most common laser eye surgery used to correct myopia (nearsightedness), hyperopia (farsightedness) and astigmatism.

LASIK corrects vision by reshaping the cornea in order to allow the light entering the eye to be properly focused onto the retina. It, like other types of refractive surgery, is usually pain-free and finished within 15 minutes for both eyes. The results of the surgery can become apparent in as little as 24 hours, and can help many people no longer need glasses or contact lenses.

The Laser Surgery Process

Your surgeon will use a surgical tool called a microkeratome or a femtosecond laser. He or she will use this tool to cut a thin, circular “flap” in the cornea.

The surgeon then folds back this flap to access the cornea underneath, called the stroma. He or she then removes some tissue using an excimer laser. This laser creates an ultraviolate light beam and removes microscopic amounts of tissue from the cornea. This reshapes it to more accurately focus light, which improves your vision.

For near-sighted people, this process is used to flatten the cornea. For far-sighted patients, this process strives to create a steeper curve in the cornea. Patients with astigmatism also have their corneas smoothed from an irregular shape into a more regular one.

After the reshaping of the cornea, the surgeon lays the flap back in place and heals naturally over time.

LASIK requires only anesthetic eye drops and has no bandages or stitches involved. It is among the least invasive surgery processes, with quick healing times.


Woman Receiving Eye Exam

Your doctor will perform a thorough eye exam to make sure you are a fitting candidate for LASIK. They will evaluate the thickness of your cornea, your pupil size, what refractive errors they must correct for (near-sightedness, far-sightedness, astigmatisim), and any other eye conditions, such as moisture.

A corneal topographer is usually used to measure the front curvature of your eye, mapping out your cornea for your surgeon. Your eyes will also be mapped out with a wavefront analysis, which sends light waves through the eye to create the most accurate portrait of your eye shape and health.

If you wear contact lenses, you will also be asked to stop wearing them for a duration determined by your doctor, as contacts can affect the shape of your cornea.

All of this, along with a general health history, will be used to determine if you are a good candidate for LASIK.

The Procedure

Numbing eye drops will be given to you at the beginning of your surgery. Your doctor may also give you medication to help you relax.

Your eye will be positioned underneath the laser and the surgeon will create the ultra-thin flap on the eye’s cornea. Afterwards, this flap is replaced, working as a sort of natural bandage for your eye as it heals.

With the flap created, the surgeon uses the computer to adjust the laser to your prescription. You then will have to look at a light for a short time while the surgeon watches your eye through a microscope as the laser does its work.

The laser pulses, and painlessly reshapes the cornea. You may feel some pressure, and will hear a steady clicking.

LASIK is performed on each eye separately, with each eye only taking about a minute.


Once your surgery is done, you may feel a bit of a burning or itching sensation. This is temporary. After a brief post-op exam, someone can drive you home. Note that you cannot drive yourself until your doctor confirms that your vision has been corrected to meet the legal standard for driving.

You may experience some blurry vision and haziness immediately following the operation, but clarity should begin to improve by the very next morning. Your eyesight should stabilize as it continues to improve with the following days, although in some rare cases it may continue to shift for several weeks. For most people, the improvement is immediate.

Most doctors recommend a couple days’ rest, though you may be able to start work the next day.

It is also recommended to avoid strenuous exercise for at least a week to avoid any potential eye trauma that could affect healing.

There is a follow up appointment with your eye doctor the day after the surgery. Here, they will test your vision and may prescribe medication as needed.

Remember to avoid rubbing your eyes.

Results of LASIK

Many people achieve 20/20 or better vision through LASIK, though results do vary. You may still need to wear eyeglasses or contacts, though your prescription should be much less. Although the procedure is incredibly safe, complications could occur and may include infection or night glare. A small number of people may need an enhancement, a small touch-up procedure. It’s important to have realistic and well-informed expectations.

LASIK is an exciting opportunity and potential replacement for glasses/contacts. If you are considering LASIK, contact your eye doctor for a LASIK consultation appointment.