How Does LASIK Work?

What is LASIK Eye Surgery?

LASIK (short for laser-assisted situ keratomileusis) is the most common laser eye surgery. It is a minimally invasive procedure that provides patients with better vision. 

LASIK surgery has one of the highest success rates, and nearly all patients are pleased with the results. In many cases, patients achieve 20/20 vision and no longer have to wear glasses or contact lenses.

"The latest research reports 99 percent of patients achieve better than 20/40 vision, and more than 90 percent achieve 20/20 or better. In addition, LASIK has an unprecedented 96 percent patient satisfaction rate – the highest of any elective procedure."

—American Refractive Surgical Council

How Does LASIK Work? (Brief Overview)

LASIK works by reshaping your corneal tissue. First, the surgeon creates a “corneal flap.” This is done with either a microkeratome (small blade) or a femtosecond laser. 

Once the incision is made, the surgeon peels back the hinged flap to access the cornea beneath (stroma). Then, an excimer laser is used. It emits cool ultraviolet light to remove microscopic amounts of your cornea. This process is called “ablation.”

The excimer laser reshapes your cornea so that your eye can focus, or refract, the light entering your eye better. This improves your eye’s focusing ability and corrects your vision.

• For nearsighted people, the laser flattens your cornea.
• For farsighted people, the laser creates a steeper cornea.
• For people with astigmatism, the laser smooths your cornea into a more spherical shape.

Once the ablation is complete, the corneal flap is put back into place, covering the altered cornea. The flap naturally heals back to the cornea during the recovery process. 

What to Expect at Your LASIK Consultation

If you are interested in LASIK surgery to correct your vision, the first step on your journey is to schedule a consultation with a qualified LASIK surgeon. Most LASIK institutes offer free consultations to determine if you are a good candidate for the procedure. 

A LASIK consultation typically lasts 2 to 3 hours. The procedure provides the surgeon with details about your eye health that determines whether or not you qualify for LASIK vision correction. If you do qualify, the surgeon will use the measurements taken at the consultation to program the laser for your surgery.

In order to prepare for your consultation, gather all available medical history, including your medical history from your general practitioner, any previous eye prescriptions, and any other eye health information you might have.

Here’s what you can expect at a LASIK consultation:

1. Medical history review. First, your eye doctor will go over your medical history. There are certain eye and general health conditions that may disqualify you from LASIK.
2. Comprehensive eye exam. The next step is a comprehensive eye exam that will analyze your refractive error, dominant eye, the health of your eye’s interior, front, and surface, eyelid health, and tear film. 
3. Corneal mapping. A corneal topography will map the shape and thickness of your cornea in extreme detail. If your cornea is thick enough, this data will be used to program the laser for your surgery.
4. Discussion of the procedure. Once your exams are finished, the surgeon will discuss the entire process with you. They will instruct you on how to prepare, including when you should stop wearing contacts and cease taking certain medications (if applicable). They should also discuss costs and payment options.
5. Time for questions and concerns. Following this discussion, there will be a time for questions. Here you can clarify any confusion you may have about preparation, the day of surgery, recovery, or costs.

If you do not qualify for LASIK surgery, your surgeon may recommend another type of refractive surgery to correct your vision. 

LASIK Procedure (Step-by-Step)

The entire LASIK surgical procedure usually lasts 30 minutes or less for both eyes. Approximately 10 minutes is needed to complete the surgery on each eye.

You are awake and alert during the procedure. Surgeons often offer a mild sedative to help you relax before the surgery.

LASIK causes little to no pain during the procedure. Your surgeon will administer local anesthetic eye drops to numb your eyes before the LASIK eye surgery begins. Many patients describe feeling a "slight pressure sensation" during the surgery. But in most cases, patients feel no pain throughout the procedure.

Here's what to expect during LASIK surgery:

Step 1: First, your eye doctor places eye drops that contain a numbing agent in your eyes. Your eyelids are held open with a tool so the eye surgeon can work. 

Step 2: The surgeon uses a small blade or special laser to cut a thin flap in your cornea. This is the part that may cause some discomfort for the patient since a suction ring is placed onto the eye just before the flap is cut. Many people report feeling "a sensation of pressure" during this part of the surgery.

Step 3: The excimer laser gently reshapes your cornea. It is guided by a computer that has a map of your eye preloaded into it.

Step 4: After the excimer laser finishes, the surgeon smooths the corneal flap back into place.

Step 5: If you are getting both eyes operated on, this process will immediately be repeated on the other eye.

Step 6: That's it, your LASIK eye surgery is complete! Once you're finished, your eye surgeon, or a team member, will provide you with an eye shield, along with detailed instructions for recovery.

LASIK Recovery

One of the reasons LASIK is so popular is because the recovery time is usually quite short. Many patients see well within 24 hours. Some even feel comfortable enough to drive or go back to work the following day. 

However, it is normal to have blurred vision for up to five days. Your surgeon will usually recommend that you rest and minimize screen time for a few days following surgery.

You will be prescribed antibiotic and steroid eye drops for a few weeks following surgery. It is very important to follow this regimen. Failure to adhere to instructions could result in infection or other serious complications. 

Common side effects following LASIK include:

• Dry eyes — Symptoms include burning, itching, gritty sensation, pain, redness, or watering.
• Halos — Halos are bright rings around a light source such as a street lamp. They are usually more apparent in dim lighting conditions.
• Glare and light sensitivity — Bright lights can cause visual discomfort or difficulty seeing.
• Difficulty with night vision — Halos and glare are more pronounced in dim lighting, making night vision more difficult.
• Hazy vision — As your corneas heal after surgery, any cloudy vision will improve over time.

Approximately 10 percent of patients will need a second LASIK treatment within 10 years of their first procedure. This is known as a LASIK enhancement. Many surgeons provide free enhancement procedures, but this varies. It’s good to ask your doctor about their policy regarding this during your consultation.

What Makes a Good LASIK Candidate?

Not everyone is eligible for LASIK surgery. However, most adults with mild vision problems, who wear glasses or contacts, will get better vision from LASIK surgery.

A good candidate fits the following 8 criteria:

1. Good general health. If you have an autoimmune disease or degenerative condition that makes it harder for your body to heal, you might not qualify for LASIK. This includes but is not limited to rheumatoid arthritis, Sjogren's syndrome, type 1 diabetes, and AIDS. Some medications, such as immunosuppressants, may also interfere with your ability to heal from eye surgery.
2. Healthy eyes. Certain conditions and eye diseases can affect your eyes' healing ability or response to refractive eye surgery. These may include severe dry eye syndrome, cataracts, or glaucoma. If you have an eye injury, conjunctivitis (pink eye), or an infection, you'll have to wait until this condition is resolved before getting eye surgery.
3. Vision that falls within a specific prescription limit. If your prescription is too high, your eye doctor may advise against laser surgery. FDA-approved excimer lasers for LASIK in the United States can correct approximately -11.00 diopters of nearsightedness, +5.00 D of farsightedness, and 5.00 D of astigmatism. However, each eye surgeon will have their own limits on how poor your vision can be.
4. Stable vision. Many people's prescriptions for glasses or contact lenses change as they age. In order to be a good candidate, your vision needs to remain stable for at least 12 months.
5. Normal cornea thickness. The LASIK surgery procedure removes part of your cornea. Your cornea needs to be sufficiently thick in order to achieve desired results.
6. Not pregnant. If you are pregnant or nursing, you should delay the procedure. Hormonal changes can alter your cornea and vision. This may take several months to return to stable levels. 
7. Normal sized pupils. People with extra-large pupils have an increased risk of side effects, including halos, glares, starbursts, and poor night vision (especially while driving)
8. Have realistic expectations. LASIK surgery has a very high success rate. However, you should be fully aware of the potential side effects and complications. 99 percent of patients achieve 20/40 vision or better, but not everyone achieves perfect vision.

Be sure to pay close attention, ask questions, and address any concerns you might have at your pre-surgery consultation. Follow all instructions your surgeon gives you very carefully.

How Much Does LASIK Cost?

The average cost of LASIK surgery in the United States is approximately $2,200 per eye or $4,400 for both.

Unfortunately, most health insurance plans do not cover LASIK surgery because they consider laser eye surgery an elective procedure. Neither Medicare nor Medicaid pays for elective eye surgery like LASIK surgery.

Some larger vision insurance carriers offer discounts on laser vision correction procedures with specific providers and frame benefits for non-prescription sunglasses after vision correction surgery. UnitedHealthcare vision insurance offers its members 35% off LASIK at over 900 locations.